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Sample records for human iron absorption

  1. Use of a standard meal to study iron absorption in humans

    International Nuclear Information System (INIS)

    Reddy, M.B.; Cook, J.D.

    1994-01-01

    Iron absorption varies widely between subjects and groups of subjects because of differences in iron status which markedly influence iron assimilation from the gastrointestinal tract. A small dose of isotopically labelled inorganic iron termed the reference dose (3 mg iron as FeSO 4 ) has been used extensively during the past two decades to standardize food iron absorption in human subjects and thereby eliminate the effect of differences in iron status. Recent studies from this laboratory have shown that because of the high variability of absorption from the reference dose, nonheme iron absorption from a standardized meal provides a more reliable means of standardizing absorption from regional diets. We therefore performed initial studies with a rice based meal but we found a relatively high variation in absorption from 2.0 to 4.7% that presumably reflects differences in the phytate content of rice fours. We then undertook the evaluation of meals prepared with farina, a wheat product that is available in most regions of the world. In six different studies from a farina based meal, iron absorption ranged from 3.4 to 6.5%. Nonheme iron absorption from the farina meal when evaluated in separate laboratories extensively engaged in human studies of iron absorption, ranged from 5.1 to 10.8% but when related to the FeSO 4 dose, a more consistent ratio between 0.21 to 0.26 was observed with the exception of one laboratory where a very low absorption of 1.1.% was observed. Percentage absorption from the farina based meal decreased when the iron content of the meal was increased and showed the expected facilitation of absorption when increasing amounts of ascorbic acid were added. By reducing variability and measuring iron absorption from food rather than inorganic iron, we believe that the use of this standard meal will facilitate comparison of iron absorption data obtained in laboratories throughout the world. 4 refs, 2 tabs

  2. Effects of iron, tin, and copper on zinc absorption in humans

    International Nuclear Information System (INIS)

    Valberg, L.S.; Flanagan, P.R.; Chamberlain, M.J.

    1984-01-01

    Zinc absorption as measured by body retention of [65Zn]zinc chloride or a turkey test meal extrinsically labeled with 65Zn was determined in human subjects by whole body counting after 7 days. Average 65Zn absorption from zinc chloride in persons with a high iron-absorbing capacity was similar to persons with a low capacity to absorb iron. Inorganic iron, 920 mumol (51 mg), or HB iron, 480 mumol (26 mg), inhibited 65Zn absorption from 92 mumol (6 mg) of zinc chloride. When 610 mumol of iron (34 mg) was added to a turkey test meal containing 61 mumol of zinc (4 mg), 65Zn absorption was not inhibited. Tin, 306 mumol (36 mg), given with zinc chloride or turkey test meals (61 mumol, 4 mg, of Zn) significantly reduced 65Zn absorption. Copper, 79 mumol (5 mg), had no significant effect on the 65Zn absorption from 7.9 mumol (0.5 mg) of zinc chloride. In summary, the capacity to absorb iron did not influence 65Zn absorption, but both inorganic iron and heme-iron inhibited 65Zn absorption from zinc chloride. Inorganic iron had no effect, however, on 65Zn absorption from the turkey test meal. Tin in a large dose also inhibited 65Zn absorption from both zinc chloride and the turkey test meal

  3. Oral iron therapy in human subjects, comparative absorption between ferrous salts and iron polymaltose

    International Nuclear Information System (INIS)

    Jacobs, P.; Johnson, G.; Wood, L.

    1984-01-01

    Iron absorption was directly compared between equivalent doses of ferrous salts and a polymaltose complex using a twin-isotope technique in which each individual acts as his own control. In the first study, bioavailability of iron from ferrous sulfate and the complex was defined at physiologic doses of 5 mg (Group 1: n = 14) and therapeutic doses of 50 mg (Group 2: n = 13). In Group 1, mean absorption from salt was 47.77% (SD 14.58%) and from polymaltose, 46.56% SD 17.07%). In Group 2, mean absorption from salt was 32.92% (SD 13.42%) and from polymaltose, 27.07% (SD 6.50%). In a second study, 100 mg of iron in a chewable formulation was used to compare absorption between equal doses of ferrous fumarate and the polymaltose complex. Mean absorption from salt was 10.25% (SD 6.89%) and from polymaltose 10.68% (SD 4.68%). At all three dosage levels, iron is equally available from salt or polymaltose for hemoglobin synthesis (p greater than 0.20), and absorption negatively correlated with plasma ferritin (p less than 0.01). These two materials may be used interchangeably in the treatment of patients with absolute iron deficiency

  4. Iron absorption studies

    International Nuclear Information System (INIS)

    Ekenved, G.

    1976-01-01

    The main objective of the present work was to study iron absorption from different iron preparations in different types of subjects and under varying therapeutic conditions. The studies were performed with different radioiron isotope techniques and with a serum iron technique. The preparations used were solutions of ferrous sulphate and rapidly-disintegrating tablets containing ferrous sulphate, ferrous fumarate and ferrous carbonate and a slow-release ferrous sulphate tablet of an insoluble matrix type (Duroferon Durules). The serum iron method was evaluated and good correlation was found between the serum iron response and the total amount of iron absorbed after an oral dose of iron given in solution or in tablet form. New technique for studying the in-vivo release properties of tablets was presented. Iron tablets labelled with a radio-isotope were given to healthy subjects. The decline of the radioactivity in the tablets was followed by a profile scanning technique applied to different types of iron tablets. The release of iron from the two types of tablets was shown to be slower in vivo than in vitro. It was found that co-administration of antacids and iron tablets led to a marked reduction in the iron absorption and that these drugs should not be administered sumultaneously. A standardized meal markedly decreased the absorbability of iron from iron tablets. The influence of the meal was more marked with rapidly-disintegrating than with slow-release ferrous sulphate tablets. The absorption from rapidly-disintegrating and slow-release ferrous sulphate tablets was compared under practical clinical conditions during an extended treatment period. The studies were performed in healthy subjects, blood donors and patients with iron deficiency anaemia and it was found that the absorption of iron from the slow-release tablets was significantly better than from the rapidly-disintegrating tablets in all three groups of subjects. (author)

  5. New perspectives on the regulation of iron absorption via cellular zinc concentrations in humans.

    Science.gov (United States)

    Knez, Marija; Graham, Robin D; Welch, Ross M; Stangoulis, James C R

    2017-07-03

    Iron deficiency is the most prevalent nutritional deficiency, affecting more than 30% of the total world's population. It is a major public health problem in many countries around the world. Over the years various methods have been used with an effort to try and control iron-deficiency anemia. However, there has only been a marginal reduction in the global prevalence of anemia. Why is this so? Iron and zinc are essential trace elements for humans. These metals influence the transport and absorption of one another across the enterocytes and hepatocytes, due to similar ionic properties. This paper describes the structure and roles of major iron and zinc transport proteins, clarifies iron-zinc interactions at these sites, and provides a model for the mechanism of these interactions both at the local and systemic level. This review provides evidence that much of the massive extent of iron deficiency anemia in the world may be due to an underlying deficiency of zinc. It explains the reasons for predominance of cellular zinc status in determination of iron/zinc interactions and for the first time thoroughly explains mechanisms by which zinc brings about these changes.

  6. Phytases for Improved Iron Absorption

    DEFF Research Database (Denmark)

    Nielsen, Anne Veller Friis; Nyffenegger, Christian; Meyer, Anne S.

    2014-01-01

    Microbial phytases (EC 3.1.3.8) catalyse dephosphorylation of phytic acid, which is the primary storage compound for phosphorous in cereal kernels. The negatively charged phosphates in phytic acid chelate iron (Fe3+) and thus retards iron bioavailability in humans 1. Supplementation of microbial...... phytase can improve iron absorption from cereal-based diets 2. In order for phytase to catalyse iron release in vivo the phytase must be robust to low pH and proteolysis in the gastric ventricle. Our work has compared the robustness of five different microbial phytases, evaluating thermal stability...

  7. Radioisotope investigation of iron absorption in humans. Part of a WHO/IAEA coordinated programme on iron nutrition

    International Nuclear Information System (INIS)

    Bothwell, T.H.

    1975-08-01

    The gastrointestinal absorption of iron was investigated in a number of multiparous women living under low socio-economic conditions which are known to lead commonly to iron deficiency. The percentage absorption was deduced by comparing the concentration of 55 Fe and/or 59 Fe in blood with the activity of the corresponding isotope(s) administered orally about two weeks earlier. It was confirmed or established that: (1) food or supplemental iron, if available at all, tends to be absorbed from the intestines as if present there in one of two alternative pools: heme and non-heme, (2) vitamin C substantially increases absorption of food or supplemental non-heme iron, (3) it is technically possible to use common salt or sugar as a carrier for supplemental iron and vitamin C, but practical difficulties of using such systems in a public health prophylactic programme are severe, and (4) tea, presumably because of its tannin content, inhibits absorption of accompanying iron

  8. Iron absorption in relation to iron status

    International Nuclear Information System (INIS)

    Magnusson, B.; Bjoern-Rasmussen, E.; Hallberg, L.; Rossander, L.

    1981-01-01

    The absorption from a 3 mg dose of ferrous iron was measured in 250 male subjects. The absorption was related to the log concentration of serum ferritin in 186 subjects of whom 99 were regular blood donors (r= -0.76), and to bone marrow haemosiderin grading in 52 subjects with varying iron status. The purpose was to try and establish a percentage absorption from such a dose that is representative of subjects who are borderline iron deficient. This information is necessary for food iron absorption studies in order (1) to calculate the absorption of iron from the diet at a given iron status and (2) compare the absorption of iron from different meals studied in different groups of subjects by different investigarors. The results suggest that an absorption of about 40% of a 3 mg reference dose of ferrous iron is given in a fasting state, roughly corresponds to the absorption in borderline-iron-deficient subjects. The results indicate that this 40% absorption value corresponds to a serum ferritin level of 30 μg/l and that food iron absorption in a group of subjects should be expressed preferably as the absorption corresponding to a reference-dose absorption of 45%, or possibly a serum ferritin level of 30 μg/l. (author)

  9. Determination of copper and iron in the human aqueous humor by atomic absorption spectrometer with graphite furnace

    International Nuclear Information System (INIS)

    Iqbal, Z.; Mohammad, Z.; Shah, M.T.; Saeed, M.; Imdadullah

    1999-01-01

    The concentration of copper and iron was determined in human aqueous humor using atomic absorption spectrophotometer equipped with graphite furnace. The mean (+- SEM) concentrations of copper (n=16) and iron (n=14) were 0.0234 -+ 0.0045 mu g.ml/sup -1/ and 0.045 -+ 0.0092 mu.ml/sup -1/ respectively. In male and female, the concentrations of copper (p< 0.82) and iron (p<0.38) were not significantly different. (author)

  10. Protein Hydrolysates as Promoters of Non-Haem Iron Absorption

    Science.gov (United States)

    Li, Yanan; Jiang, Han; Huang, Guangrong

    2017-01-01

    Iron (Fe) is an essential micronutrient for human growth and health. Organic iron is an excellent iron supplement due to its bioavailability. Both amino acids and peptides improve iron bioavailability and absorption and are therefore valuable components of iron supplements. This review focuses on protein hydrolysates as potential promoters of iron absorption. The ability of protein hydrolysates to chelate iron is thought to be a key attribute for the promotion of iron absorption. Iron-chelatable protein hydrolysates are categorized by their absorption forms: amino acids, di- and tri-peptides and polypeptides. Their structural characteristics, including their size and amino acid sequence, as well as the presence of special amino acids, influence their iron chelation abilities and bioavailabilities. Protein hydrolysates promote iron absorption by keeping iron soluble, reducing ferric iron to ferrous iron, and promoting transport across cell membranes into the gut. We also discuss the use and relative merits of protein hydrolysates as iron supplements. PMID:28617327

  11. Protein Hydrolysates as Promoters of Non-Haem Iron Absorption

    Directory of Open Access Journals (Sweden)

    Yanan Li

    2017-06-01

    Full Text Available Iron (Fe is an essential micronutrient for human growth and health. Organic iron is an excellent iron supplement due to its bioavailability. Both amino acids and peptides improve iron bioavailability and absorption and are therefore valuable components of iron supplements. This review focuses on protein hydrolysates as potential promoters of iron absorption. The ability of protein hydrolysates to chelate iron is thought to be a key attribute for the promotion of iron absorption. Iron-chelatable protein hydrolysates are categorized by their absorption forms: amino acids, di- and tri-peptides and polypeptides. Their structural characteristics, including their size and amino acid sequence, as well as the presence of special amino acids, influence their iron chelation abilities and bioavailabilities. Protein hydrolysates promote iron absorption by keeping iron soluble, reducing ferric iron to ferrous iron, and promoting transport across cell membranes into the gut. We also discuss the use and relative merits of protein hydrolysates as iron supplements.

  12. Bioavailability & absorption of Iron and Anemia

    Directory of Open Access Journals (Sweden)

    Radhika Kapil

    2018-01-01

    Full Text Available Humans derive iron from their everyday diet, predominantly from plant foods and the rest from foods of animal origin. Iron is found in food as either haem or non-haem iron.  Haem iron, which is about up to 40 per cent of the iron in meat, poultry, and fish, is well absorbed.  All the iron in plants (fruits, vegetables, grains, nuts is in the form of non-haem iron and is relatively poorly absorbed. Non-haem iron contributes about 90-95 per cent of total daily iron in vegan diets. In western countries,the intake of haem iron from meat and meat products accounts for bulk of the dietary iron. The haem iron consumption is minimal in developing countries with majority obtaining non-haem iron from cereals, pulses, vegetables and fruits'. The diets is plagued by low iron content and poor absorption. Major sources of non-haem iron are plant foods. The iron is chemically diverse, ranging from simple iron oxides and salts to more complex organic chelates such as hydroxyphosphates in phytoferritin(1.

  13. Bioavailability & absorption of Iron and Anemia

    Directory of Open Access Journals (Sweden)

    Radhika Kapil

    2017-12-01

    Full Text Available Humans derive iron from their everyday diet, predominantly from plant foods and the rest from foods of animal origin. Iron is found in food as either haem or non-haem iron.  Haem iron, which is about up to 40 per cent of the iron in meat, poultry, and fish, is well absorbed.  All the iron in plants (fruits, vegetables, grains, nuts is in the form of non-haem iron and is relatively poorly absorbed. Non-haem iron contributes about 90-95 per cent of total daily iron in vegan diets. In western countries,the intake of haem iron from meat and meat products accounts for bulk of the dietary iron. The haem iron consumption is minimal in developing countries with majority obtaining non-haem iron from cereals, pulses, vegetables and fruits'. The diets is plagued by low iron content and poor absorption. Major sources of non-haem iron are plant foods. The iron is chemically diverse, ranging from simple iron oxides and salts to more complex organic chelates such as hydroxyphosphates in phytoferritin(1.

  14. Phytases for improved iron absorption

    DEFF Research Database (Denmark)

    Nielsen, Anne Veller Friis; Meyer, Anne S.

    2016-01-01

    Phytase enzymes present an alternative to iron supplements, because they have been shown to improve iron absorption by means of catalysing the degradation of a potent iron absorption inhibitor: phytic acid. Phytic acid is a hexaphosphate of inositol and is particularly prevalent in cereal grains......, where it serves as a storage molecule for phosphorous. Phytic acid is also associated with minerals. The minerals are bound by chelation to the negatively charged phosphate groups in phytic acid. Phytases catalyse the dephosphorylation of phytic acid, thus releasing bound minerals to make them available...... for absorption. This article presents research on phytase catalysis in gastric conditions and considers potential benefits and drawbacks for using phytases as a food supplement....

  15. Absorption of medicamental iron and iron from food

    International Nuclear Information System (INIS)

    Reizenstein, P.; Carlmark, B.; Ehn, L.; Forsberg, K.; Hoeglund, S.; Terpstra, T.

    1976-01-01

    Methods are reviewed for the measurement of iron absorption. The chemical balance method has been almost entirely supplanted by radioisotope methods, which include notably whole-body counting and measurement of incorporation of radioiron into red cells. A survey is also given of the various conditions that influence iron absorption, including chemical form of iron, amount of iron, accompanying diet. Absorption tests must be conducted under relevant conditions. (author)

  16. Absorption of controlled-release iron

    International Nuclear Information System (INIS)

    Cook, J.D.; Lipschitz, D.A.; Skikne, B.S.

    1982-01-01

    A multiple-dose double radioiron technic was used to compare absorption of iron administered as a controlled release (CR) capsule and as an elixir; both formulations contained 50 mg elemental iron as ferrous sulfate. When taken by normal subjects in the fasting state, mean absorption from the elixir and CR capsule averaged 4.92% and 4.38%, which gave a CR capsule:elixir ratio of 0.89. This difference was not significant, but when taken with meals that inhibit absorption of dietary iron by different degrees, absorption of the CR formulation was superior. CR capsule:elixir absorption ratios averaged 1.70 from a meal that is mildly inhibitory and 3.13 from a meal that causes more marked inhibition. It is concluded that CR iron formulations may offer a therapeutic advantage to patients who take oral iron with meals to avoid gastrointestinal side effects

  17. Iron absorption from adequate Filipinos meals

    International Nuclear Information System (INIS)

    Trinidad, T.P.; Madriaga, J.R.; Valdez, D.H.; Cruz, E.M.; Mallillin, A.C.; Sison, C.C.; Kuizon, M.D.

    1989-01-01

    Iron absorption from adequate Filipino meals representing the three major island groups of the Philippines (Luzon, Visayas, and Mindanao) was studied using double isotope extrinsic tag method. Mean iron absorption of the one-day meal for Metro Manila was 6.6 +- 1.26%. Central Visayas, 6.3 +- 1.15% and Southern Mindanao, 6.4 +- 1.19%. Comparison between meals (breakfast, lunch, dinner) for each region as well as one-day meal for the three regions showed no significant differences (P>0.01). Correlation tests done between iron absorption and the following iron enhancers: ascorbic acid, amount of fish, meat or poultry; and inhibitors: phytic acid and tannic acid, did not give significant results. The overall average of 6.4 +- 1.20% may be used as the iron absorption level from an adequate Filipino meal. This value can be considered as one of the bases for arriving at recommended dietary allowances for iron among Filipinos instead of the 10% iron absorption assumed in 1976. (Auth.). 21 refs.; 3 tabs.; 3 annexes

  18. Iron absorption from adequate Filipino meals

    International Nuclear Information System (INIS)

    Trinidad, T.P.; Madriaga, J.R.; Valdez, D.H.; Cruz, E.M.; Mallillin, A.C.; Sison, C.C.; Kuizon, M.D.

    1991-01-01

    Iron absorption from adequate Filipino meals representing the three major island groups of the Philippines (Luzon, Visayas and Mindanao) was studied using double isotope extrinsic tag method. Mean iron absorption of the one-day meal for Metro Manila was 6.6 ± 1.26%, Central Visayas, 6.3 ± 1.15% and Southern Mindanao, 6.4 ± 1.19%. Comparison between meals (breakfast, lunch, dinner) for each region as well as one-day meal for the three regions showed no significant differences (P > .01). Correlation tests done between iron absorption and the following iron enhancers: ascorbic acid, amount of fish, meat or poultry and inhibitors: phytic acid and tannic acid did not give significant results. The overall bar x of 6.4 ± 1.20% may be used as the non-heme iron absorption level from an adequate Filipino meal. This value can be considered as one of the bases for arriving at recommended dietary allowances for iron among Filipinos instead of the 10% iron absorption assumed in 1976

  19. Comparison of colorimetry and electrothermal atomic absorption spectroscopy for the quantification of non-transferrin bound iron in human sera.

    Science.gov (United States)

    Jittangprasert, Piyada; Wilairat, Prapin; Pootrakul, Pensri

    2004-12-01

    This paper describes a comparison of two analytical techniques, one employing bathophenanthrolinedisulfonate (BPT), a most commonly-used reagent for Fe (II) determination, as chromogen and an electrothermal atomic absorption spectroscopy (ETAAS) for the quantification of non-transferrin bound iron (NTBI) in sera from thalassemic patients. Nitrilotriacetic acid (NTA) was employed as the ligand for binding iron from low molecular weight iron complexes present in the serum but without removing iron from the transferrin protein. After ultrafiltration the Fe (III)-NTA complex was then quantified by both methods. Kinetic study of the rate of the Fe (II)-BPT complex formation for various excess amounts of NTA ligand was also carried out. The kinetic data show that a minimum time duration (> 60 minutes) is necessary for complete complex formation when large excess of NTA is used. Calibration curves given by colorimetric and ETAAS methods were linear over the range of 0.15-20 microM iron (III). The colorimetric and ETAAS methods exhibited detection limit (3sigma) of 0.13 and 0.14 microM, respectively. The NTBI concentrations from 55 thalassemic serum samples measured employing BPT as chromogen were statistically compared with the results determined by ETAAS. No significant disagreement at 95% confidence level was observed. It is, therefore, possible to select any one of these two techniques for determination of NTBI in serum samples of thalassemic patients. However, the colorimetric procedure requires a longer analysis time because of a slow rate of exchange of NTA ligand with BPT, leading to the slow rate of formation of the colored complex.

  20. Effects of Omeprazole on Iron Absorption: Preliminary Study

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    Mahmut Yaşar Çeliker

    2013-09-01

    Full Text Available Objective: Increasing numbers of pediatric and adult patients are being treated with proton pump inhibitors (PPIs. PPIs are known to inhibit gastric acid secretion. Nonheme iron requires gastric acid for conversion to the ferrous form for absorption. Ninety percent of dietary and 100% of oral iron therapy is in the nonheme form. To the best of our knowledge, the effect of PPIs on iron absorption has not been studied in humans. Our study assessed the relationship between omeprazole therapy and iron absorption in healthy subjects. Materials and Methods: We recruited 9 healthy volunteers between June 2010 and March 2011. Subjects with chronic illness, anemia, or use of PPI therapy were excluded. Serum iron concentrations were measured 1, 2, and 3 h after the ingestion of iron (control group. The measurements were repeated on a subsequent visit after 4 daily oral administrations of omeprazole at a dose of 40 mg (treatment group. Results: One female and 8 male volunteers were enrolled in the study with a mean age of 33 years. There was no statistical difference detected between baseline, 1-h, 2-h, and 3-h iron levels between control and treatment groups. Conclusion: Administration of omeprazole for a short duration does not affect absorption of orally administered iron in healthy individuals.

  1. Iron absorption after antrectomy with gastroduodenostomy

    International Nuclear Information System (INIS)

    Magnusson, B.E.O.

    1976-01-01

    Haematological values were studied in 177 unselected patients 3-6 years after antrectomy with gastroduodenostomy. The majority (76%) had been operated upon for duodenal ulcer, 20% for gastric ulcer and the remaining patients had had both a duodenal and a gastric ulcer before the operation. In 65 patients a vagotomy had been added to the resection. 10% of the males and 15% of the females had a haemoglobin concentration below 13.0 or 12.0 g/100 ml, respectively. The corresponding frequencies for iron defifiency, defined as absence or only traces of haemosiderin in bone marrow smears, were 7% and 15%. The absorption of a small test dose of inorganic iron (0.56 mg Fe ++ as ferrous ascorbate) was studied in all the antrectomized patients. The absorption was also investigated in normal men and in patients who had had a Billroth II partial gastrectomy. No malabsorption of inorganic iron could be found in any of the groups. An inverse relationship between iron absorption and the grading of haemosiderin in bone marrow smears was found in normal subjects as well as in operated patients. Thus, an adequate increase of the absorption of ferrous iron was found even in operated patients with iron deficiency. Gastric acid secretion, measured as the peak acid output (PAO) after stimulation, was determined in all antrectomized patients. In patients having the same grading of haemosiderin (grade II) a slight but significant positive correlation was found between PAO and the absorption from the test dose (Fe ++ ). The absorption of food iron from a composite meal and the absorption from an iron salt (3.0 mg Fe ++ as ferrous ascorbate) was studied in 4 different groups: 1) normal males, 2) non-operated patients with peptic ulcer, 3) antrectomized patients with gastroduodenostomy and 4) patients operated upon with Billroth II partial gastrectomy. The range and mean absorption values from the test dose of inorganic iron were about the same in all groups. The absorption of food iron

  2. Measurement of iron absorption from meals contaminated with iron

    International Nuclear Information System (INIS)

    Hallberg, L.; Bjoern-Rasmussen, E.

    1981-01-01

    A method is described to measure in vitro the extent of isotopic exchange between the native nonheme food iron and added inorganic reduction to radioiron tracer. The food is digested with pepsin and trypsin in the presence of radioiron. The exchangeability of food iron is calculated from the specific activity in the food and in an extract of bathophenantroline in isoamyl alcohol obtained after digesting this food. The precision and accuracy of the method is illustrated by two kinds of studies, those in which different amounts of contamination iron are added to a meal and those evaluating contamination iron in natural meals. The present method will make it possible to measure validly iron absorption from meals contaminated with unknown amounts of iron of unknown exchangeability with the extrinsic radioiron tracer

  3. Iron, lead, and cobalt absorption: similarities and dissimilarities

    International Nuclear Information System (INIS)

    Barton, J.C.; Conrad, M.E.; Holland, R.

    1981-01-01

    Using isolated intestinal segments in rats, the absorption of iron, lead, and cobalt was increased in iron deficiency and decreased in iron loading. Similarly, the absorption of these metals was decreased in transfusional erythocytosis, after intravenous iron injection and after parenteral endotoxin injection. Acute bleeding or abbreviated intervals of dietary iron deprivation resulted in increased iron absorption from isolated intestinal segments and in intact animals, while the absorption of lead and cobalt was unaffected. These results suggest that the specificity of the mucosal metal absorptive mechanism is either selectively enhanced for iron absorption by phlebotomy or brief periods of dietary iron deprivation, or that two or more mucosal pathways for iron absorption may exist

  4. Absorption of plutonium in the iron-deficient rat

    International Nuclear Information System (INIS)

    Ragan, H.A.

    1977-01-01

    Iron deficiency did not enhance absorption of plutonium following intragastric gavage of rats. Absorption of plutonium citrate in both control and iron-deficient rats was about 0.03% of the administered dose

  5. Effects of divalent amino acids on iron absorption

    International Nuclear Information System (INIS)

    Christensen, J.M.; Ghannam, M.; Ayres, J.W.

    1984-01-01

    Solutions of each of 10 amino acids or ascorbic acid were mixed with iron and orally administered to rats. Iron was absorbed to a statistically significantly greater extent when mixed with asparagine, glycine, serine, or ascorbic acid as compared with a control solution of iron. The largest effects were for asparagine and glycine, which also increased iron absorption to a significantly greater extent than did serine or ascorbic acid. No statistically significant increase in iron absorption occurred when any of the other amino acids was mixed with iron. The extent of iron absorption from each test solution, as measured by area under the concentration of iron-59 in the blood-time curve (r2 . 0.0002), and the initial rate of iron absorption for each test solution (r2 . 0.01) showed no correlation with the stability constant of the amino acid-iron complex

  6. Does lead use the intestinal absorptive pathways of iron? Impact of iron status on murine 210Pb and 59Fe absorption in duodenum and ileum in vivo

    International Nuclear Information System (INIS)

    Elsenhans, Bernd; Janser, Heinz; Windisch, Wilhelm; Schuemann, Klaus

    2011-01-01

    Highlights: → Absorption of 210 Pb increases much less than that of 59 Fe in murine duodena. → 210 Pb-absorption is almost equally high in murine duodenal and ileal segments. → 59 Fe absorption is much lower in ileal than in duodenal segments. → There must be an additional DMT1-independet pathway for intestinal Pb absorption. -- Abstract: Background: Human isotope studies and epidemiological trials are controversial as to whether lead absorption shares the absorptive pathways of iron and whether body lead content can be reduced by iron supplementation. Aim: To compare the impact of iron-deficiency on 59 Fe- and 210 Pb-absorption rates in duodenal and ileal segments. Methods: 59 Fe- and 210 Pb-absorption was determined in ligated duodenal and ileal segments from juvenile and adult iron-deficient and iron-adequate C57Bl6 wild-type mice (n = 6) in vivo at luminal concentrations corresponding to human exposure (Fe: 1 and 100 μmol/L; Pb: 1 μmol/L). Results and discussion: 59 Fe-absorption increased 10-15-fold in iron-deficient duodena from adult and adolescent mice. Ileal 59 Fe-absorption was 4-6 times lower than in iron-adequate duodena showing no adaptation to iron-deficiency. This in accordance to expectation as the divalent metal transport 1 (DMT1) shows low ileal expression levels. Juvenile 59 Fe-absorption was about twice as high as in adult mice. In contrast, duodenal 210 Pb-absorption was increased only 1.5-1.8-fold in iron-deficiency in juvenile and adult mice and, again in contrast to 59 Fe, ileal 210 Pb-absorption was as high as in iron-adequate duodena. Conclusions: The findings suggest a DMT1-independent pathway to mediate lead absorption along the entire small intestine in addition to DMT1-mediated duodenal uptake. Ileal lead absorption appears substantial, due the much longer residence of ingesta in the distal small intestine. Differences in lead-solubility and -binding to luminal ligands can, thus, explain the conflicting findings regarding the

  7. Iron-59 absorption from soy hulls: intrinsic vs extrinsic labeling

    International Nuclear Information System (INIS)

    Lykken, G.I.; Mahalko, J.R.; Nielsen, E.J.; Dintzis, F.R.

    1986-01-01

    As part of an evaluation of the validity of the extrinsic labeling technique for measuring iron absorption, absorption from soy hulls extrinsically labeled ( 59 Fe added to bread dough) was compared with that from soy hulls intrinsically labeled ( 59 Fe incorporated into the soy plant during growth). Century soybeans were grown in a greenhouse. After pods had formed and were filling, each plant was stem injected twice, at 3 day intervals, with 22 μCi 59 Fe as FeCl 2 in 25 μl of 0.5 M HCl solution. After the plants had senesced, the soybeans were harvested, dried, shelled and the hulls removed. Standard meals containing 3.5 mg Fe/meal and up to 0.06 μCi 59 Fe in a soy hull bun were fed on 2 consecutive days to free-living volunteers in a crossover design. Absorption of 59 Fe was greater from intrinsically labeled soy hulls than from extrinsically labeled soy hulls, 20 +/- 20% vs 15 +/- 11% (n=14, p > 0.05 by paired t-test). Apparent absorption ranged from 1.3% to 77% from intrinsically labeled soy hulls and .5% to 29% from extrinsically labeled soy hulls with the highest absorption occurring in persons with low serum ferritin (S.F. < 8 ng/ml). These findings provide additional evidence that the extrinsic labeling method is a valid measure of iron bioavailability to humans

  8. Serum hepcidin is significantly associated with iron absorption from food and supplemental sources in healthy young woman

    Science.gov (United States)

    Hepcidin is a key regulator of iron homeostasis, but to date no studies have examined the effect of hepcidin on iron absorption in humans. Our objective was to assess relations between both serum hepcidin and serum prohepcidin with nonheme-iron absorption in the presence and absence of food with the...

  9. Bioavailable iron in typical Thai meals: Comparative studies between radioactive in vitro and in vivo food iron absorption measurements

    International Nuclear Information System (INIS)

    Sritongkul, N.

    1989-03-01

    Presently available in vivo methods for assessing iron absorption in human subjects, although physiologically acceptable and accurate, are not practical for screening large numbers of food and diet samples. A simple in vitro method for determining the amount of iron available for absorption was therefore investigated. It is based on the common pool concept of food iron absorption using radioactive Fe-59 as a marker of the iron present in the bioavailable iron pool. The ionizable iron was measured after an initial peptic digestion by using pepsin/HCl at pH 1.35 followed by an increase of the pH to 6.0 to simulate duodenal alkalinity. The method was proved to be simple, reproducible and applicable either to single food items or whole meals of varying composition. It is able to detect known enhancers or inhibitors of food iron absorption. The percent ionizable iron among 5 different meals with the inclusion of inhibitor or enhancer was shown to correlate closely with the percentage of iron absorbed in human subjects (r=0.9197, p<0.001). A high correlation between the in vivo and in vitro methods was also observed when the results were expressed as absorption ratios and ionizable ratios (r=0.9192, p<0.001). The method is expected to be useful for improving diet composition to increase the iron availability of some typical meals in developing countries, including those which are known to contain considerable amounts of inhibitors of iron absorption. 39 refs, 1 fig., 13 tabs

  10. Iron metabolism in experimental rickets. Pt. 1. Intestinal absorption of iron in rat rickets

    International Nuclear Information System (INIS)

    Pronicka, E.

    1975-01-01

    Investigations were carried out on iron 59 Fe absorption in rats with experimental rickets. It was found that rats with rickets as compared with controls do not show any significant differences in the degree of iron absorption in fasting state. The percent of absorbed iron increases when it is administered after previous feeding of rats. A greater rise in iron absorption after feeding was shown also by rats with rickets. On the other hand, administration of a shock dose of vitamin D at the time of rickets development causes after 7 days a significant decrease in total iron absorption given to fed rats. An excess of calcium in the diet of rats does not seem to impair directly the absorption of iron. The possibility of the causative effect of vitamin D deficiency on the composition of intestinal contents on changes in the degree of iron absorption observed after feeding of rats with rickets, is discussed. (author)

  11. Iron metabolism in experimental rickets. I. Intestinal absorption of iron in rat rickets

    Energy Technology Data Exchange (ETDEWEB)

    Pronicka, E [Pomorska Akademia Medyczna, Szczecin (Poland)

    1975-01-01

    Investigations were carried out on iron /sup 59/Fe absorption in rats with experimental rickets. It was found that rats with rickets as compared with controls do not show any significant differences in the degree of iron absorption in fasting state. The percent of absorbed iron increases when it is administered after previous feeding of rats. A greater rise in iron absorption after feeding was shown also by rats with rickets. On the other hand, administration of a shock dose of vitamin D at the time of rickets development causes after 7 days a significant decrease in total iron absorption given to fed rats. An excess of calcium in the diet of rats does not seem to impair directly the absorption of iron. The possibility of the causative effect of vitamin D deficiency on the composition of intestinal contents on changes in the degree of iron absorption observed after feeding of rats with rickets, is discussed.

  12. Absorption from iron tablets given with different types of meals.

    Science.gov (United States)

    Hallberg, L; Björn-Rasmussen, E; Ekenved, G; Garby, L; Rossander, L; Pleehachinda, R; Suwanik, R; Arvidsson, B

    1978-09-01

    The absorption of iron from tablets given with 5 types of meals was studied in 153 subjects. The meals were: a hamburger meal with beans and potatoes, a simple breakfast meal, a Latin American meal composed of black beans, rice and maize and two Southeast Asian meals composed of rice, vegetables and spices served with and without fish. The groups were directly compared by relating the absorption from the iron tablets to the absorption from a standardized reference dose of iron given on an empty stomach. The composition of meals with respect to content of meat or fish or the presence of large amounts of phytates seemed to have no influence on the absorption of iron from tablets. The absorption from iron tablets was about 40% higher when they were given with rice meals than when they were given with the other meals studied. The average decrease in absorption by meals was about 50-60% based on a comparison when tablets were given on an empty stomach. When tablets from which the iron was released more slowly were used, the absorption increased by about 30% except when they were given with rice meals, where the absorption was unchanged. The differences among the meals in their effect on the absorption of iron from tablets thus disappeared when the slow-release tablets were given.

  13. Absorption from iron tablets given with different types of meals

    Energy Technology Data Exchange (ETDEWEB)

    Hallberg, L; Bjoern-Rasmussen, E; Ekenved, G; Garby, L; Rossander, L; Pleehachinda, R; Suwanik, R; Arvidsson, B

    1978-01-01

    The absorption from iron tablets given with 5 types of meals was studied in 153 subjects. The meals were: a hamburger meal with beans and potatoes, a simple breakfast meal, a Latin American meal composed of black beans, rice and maize and two Southeast Asian meals composed of rice, vegetables, and spices served with and without fish. The groups were directly compared by relating the absorption from the iron tablets to the absorption from a standardized reference dose of iron given on an empty stomach. The composition of meals with respect to content of meat or fish or the presence of large amounts of phytates seemed to have no influence on the absorption of iron from tablets. The absorption from iron tablets was about 40% higher when they were given with rice meals than when they were given with the other meals studied. The average decrease in absorption by meals was about 50-60% based on a comparison when tablets were given on an empty stomach. When tablets from which the iron was released more slowly were used, the absorption increased by about 30% except when they were given with rice meals, where the absorption was unchanged. The differences among the meals in their effect on the absorption of iron from tablets thus disappeared when the slow-release tablets were given.

  14. Absorption from iron tablets given with different types of meals

    International Nuclear Information System (INIS)

    Hallberg, L.; Bjoern-Rasmussen, E.; Ekenved, G.; Garby, L.; Rossander, L.; Pleehachinda, R.; Suwanik, R.; Arvidsson, B.

    1978-01-01

    The absorption from iron tablets given with 5 types of meals was studied in 153 subjects. The meals were: a hamburger meal with beans and potatoes, a simple breakfast meal, a Latin American meal composed of black beans, rice and maize and two Southeast Asian meals composed of rice, vegetables, and spices served with and without fish. The groups were directly compared by relating the absorption from the iron tablets to the absorption from a standardized reference dose of iron given on an empty stomach. The composition of meals with respect to content of meat or fish or the presence of large amounts of phytates seemed to have no influence on the absorption of iron from tablets. The absorption from iron tablets was about 40% higher when they were given with rice meals than when they were given with the other meals studied. The average decrease in absorption by meals was about 50-60% based on a comparison when tablets were given on an empty stomach. When tablets from which the iron was released more slowly were used, the absorption increased by about 30% except when they were given with rice meals, where the absorption was unchanged. The differences among the meals in their effect on the absorption of iron from tablets thus disappeared when the slow-release tablets were given. (author)

  15. Dietary hemoglobin rescues young piglets from severe iron deficiency anemia: Duodenal expression profile of genes involved in heme iron absorption.

    Directory of Open Access Journals (Sweden)

    Robert Staroń

    Full Text Available Heme is an efficient source of iron in the diet, and heme preparations are used to prevent and cure iron deficiency anemia in humans and animals. However, the molecular mechanisms responsible for heme absorption remain only partially characterized. Here, we employed young iron-deficient piglets as a convenient animal model to determine the efficacy of oral heme iron supplementation and investigate the pathways of heme iron absorption. The use of bovine hemoglobin as a dietary source of heme iron was found to efficiently counteract the development of iron deficiency anemia in piglets, although it did not fully rebalance their iron status. Our results revealed a concerted increase in the expression of genes responsible for apical and basolateral heme transport in the duodenum of piglets fed a heme-enriched diet. In these animals the catalytic activity of heme oxygenase 1 contributed to the release of elemental iron from the protoporphyrin ring of heme within enterocytes, which may then be transported by the strongly expressed ferroportin across the basolateral membrane to the circulation. We hypothesize that the well-recognized high bioavailability of heme iron may depend on a split pathway mediating the transport of heme-derived elemental iron and intact heme from the interior of duodenal enterocytes to the bloodstream.

  16. Atomic absorption assessment of mineral iron quantity in ferritin

    International Nuclear Information System (INIS)

    Marinova, M.; Vladimirova, L.

    2009-01-01

    Possibilities for quantitative determination of the number of iron atoms in the mineral core of ferritin by atomic absorption spectroscopy (AAS) are investigated in the work. Different measurements with AAS show an iron content from 1000 up to 4500 atoms per molecule ferritin. This motivated us to investigate the amount of iron in the Horse Spleen Ferritin with atomic absorption spectroscopy under application of the Bulgarian standard BDS EN 14082/2003 Foodstuffs - Determination of trace elements - Determination of lead, cadmium, zinc, copper, iron and chromium by atomic absorption spectrometry (AAS) after dry ashing. The obtained results give approx. 1800 atoms per molecule Ferritin. It is in accordance with previous results, published by leading researchers. The investigation of the iron content with AAS under the use of the Bulgarian standard is a good opportunity to study many other objects of biological interest. (authors)

  17. Deciphering the iron isotope message of the human body

    Science.gov (United States)

    Walczyk, Thomas; von Blanckenburg, Friedhelm

    2005-04-01

    Mass-dependent variations in isotopic composition are known since decades for the light elements such as hydrogen, carbon or oxygen. Multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS) and double-spike thermal ionization mass spectrometry (TIMS) permit us now to resolve small variations in isotopic composition even for the heavier elements such as iron. Recent studies on the iron isotopic composition of human blood and dietary iron sources have shown that lighter iron isotopes are enriched along the food chain and that each individual bears a certain iron isotopic signature in blood. To make use of this finding in biomedical research, underlying mechanisms of isotope fractionation by the human body need to be understood. In this paper available iron isotope data for biological samples are discussed within the context of isotope fractionation concepts and fundamental aspects of human iron metabolism. This includes evaluation of new data for body tissues which show that blood and muscle tissue have a similar iron isotopic composition while heavier iron isotopes are concentrated in the liver. This new observation is in agreement with our earlier hypothesis of a preferential absorption of lighter iron isotopes by the human body. Possible mechanisms for inducing an iron isotope effect at the cellular and molecular level during iron uptake are presented and the potential of iron isotope effects in human blood as a long-term measure of dietary iron absorption is discussed.

  18. The effect of psychological stress on iron absorption in rats

    Directory of Open Access Journals (Sweden)

    Zhao Min

    2009-11-01

    Full Text Available Abstract Background Psychological stress (PS is recognized as an important pathogenic factor which leads to metabolism disorder in many diseases. Previous studies have shown that systemic iron homeostasis in mammalians was changed under specific stress conditions. Methods In present study, we used communication box to create psychological stress model and investigated the iron apparent absorption, iron accumulation in the apical poles of villous enterocytes and protein expressions of ferroportin 1 (FPN1, ferritin, divalent metal transporter 1 (DMT1. Results Our study showed that iron apparent absorption decreased and iron significantly accumulated in the apical poles of villous enterocytes in 3 d and 7 d PS groups. The expression of intestinal FPN1 in 3 d and 7 d PS groups was lower than that of control, while the change of intestinal ferritin was opposite. However, the expression of DMT1 did not change. Conclusion These results demonstrate that PS can decrease iron absorption in rats, which might be related to regulation expression of iron transporters.

  19. Iron absorption from beans with different contents of iron, evaluated by stable isotopes.

    Science.gov (United States)

    Junqueira-Franco, Márcia Varella Morandi; Dutra de Oliveira, José Eduardo; Nutti, Marilia Regini; Pereira, Helton Santos; Carvalho, José Luiz Vianna de; Abrams, Steven A; Brandão, Camila Fernanda Cunha; Marchini, Júlio Sérgio

    2018-06-01

    The introduction of biofortified foods such as beans with higher iron content may be a useful tool in preventing iron deficiency. The biofortification aims to reach the root of the problem of malnutrition, targets the neediest population, uses embedded distribution mechanisms, is scientifically feasible and effective in terms of cost, and complements other ongoing interventions to control micronutrient deficiency. However, to ensure effectiveness, measurement of the absorption of minerals is essential. The objective of this study was to evaluate the iron bioavailability of common bean BRS Pontal (PO), targeted for biofortification, compared with common bean BRS Estilo in man through reliable techniques that have not been previously used in Brazil. The study included 29 young adult volunteers divided into 2 groups: Group CB (13 subjects) received 100 g of common beans (BRS-Estilo) cooked labeled with iron-58 ( 58 Fe) and Group TBB (16 patients) received 100 g common bean target for iron biofortification (BRS-Pontal), cooked and labeled with iron58 ( 58 Fe). The next day they received the reference dose of ferrous sulfate enriched iron-57 ( 57 Fe). Isotopic evaluation of iron for measurement of iron incorporation into erythrocytes was performed 14 days after consumption. The beans used, were produced, through conventional breeding program, by EMBRAPA/Rice and Beans. The iron absorption was evaluated by assessing the isotopic enrichment of the stable isotope. Mean iron absorption from the meal with common beans was 0.409% (±0.040%) and mean iron incorporation from the meal with target beans for biofortification 0.407% (±0.038%) and did not differ between the groups. This study tested the iron absorption from a single bean meal in healthy volunteers or non anemics, In the present study the iron absorption ratio from common bean Pontal (PO), targeted for biofortification and compared with common bean BRS Estilo was not significantly different. The iron concentration

  20. Iron Absorption from Two Milk Formulas Fortified with Iron Sulfate Stabilized with Maltodextrin and Citric Acid

    Directory of Open Access Journals (Sweden)

    Fernando Pizarro

    2015-10-01

    Full Text Available Background: Fortification of milk formulas with iron is a strategy widely used, but the absorption of non-heme iron is low. The purpose of this study was to measure the bioavailability of two iron fortified milk formulas designed to cover toddlers´ nutritional needs. These milks were fortified with iron sulfate stabilized with maltodextrin and citric acid. Methods: 15 women (33–47 years old participated in study. They received on different days, after an overnight fast, 200 mL of Formula A; 200 mL of Formula B; 30 mL of a solution of iron and ascorbic acid as reference dose and 200 mL of full fat cow’s milk fortified with iron as ferrous sulfate. Milk formulas and reference dose were labeled with radioisotopes 59Fe or 55Fe, and the absorption of iron measured by erythrocyte incorporation of radioactive Fe. Results: The geometric mean iron absorption corrected to 40% of the reference dose was 20.6% for Formula A and 20.7% for Formula B, versus 7.5% of iron fortified cow’s milk (p < 0.001. The post hoc Sheffé indeed differences between the milk formulas and the cow’s milk (p < 0.001. Conclusion: Formulas A and B contain highly bioavailable iron, which contributes to covering toddlers´ requirements of this micronutrient.

  1. Nonradioisotopic method for measuring iron absorption from a Gambian meal

    International Nuclear Information System (INIS)

    Fairweather-Tait, S.J.; Minski, M.J.; Singh, J.

    1987-01-01

    Iron absorption from a typical Gambian meal of rice with groundnut sauce was measured by the fecal balance technique in nonanemic adult males with 58 Fe as an extrinsic label and neutron activation analysis and compared with ferrous sulfate. Gambian men had a higher efficiency of absorption than UK volunteers but the availability of the food Fe was approximately half that of ferrous sulfate in both groups of subjects

  2. Quantification of body iron and iron absorption in the REDS-II Donor Iron Status Evaluation (RISE) study.

    Science.gov (United States)

    Kiss, Joseph E; Birch, Rebecca J; Steele, Whitney R; Wright, David J; Cable, Ritchard G

    2017-07-01

    Repeated blood donation alters the iron balance of blood donors. We quantified these effects by analyzing changes in body iron as well as calculating iron absorbed per day for donors enrolled in a prospective study. For 1308 donors who completed a final study visit, we calculated total body iron at the enrollment and final visits and the change in total body iron over the course of the study. Taking into account iron lost from blood donations during the study and obligate losses, we also calculated the average amount of iron absorbed per day. First-time/reactivated donors at enrollment had iron stores comparable to previous general population estimates. Repeat donors had greater donation intensity and greater mean iron losses than first-time/reactivated donors, yet they had little change in total body iron over the study period, whereas first-time/reactivated donors had an average 35% drop. There was higher estimated iron absorption in the repeat donors (men: 4.49 mg/day [95% confidence interval [CI], 4.41-4.58 mg/day]; women: 3.75 mg/day [95% CI, 3.67-3.84 mg/day]) compared with estimated iron absorption in first-time/reactivated donors (men: 2.89 mg/day [95% CI, 2.75-3.04 mg/day]; women: 2.76 mg/day [95% CI, 2.64-2.87 mg/day]). The threshold for negative estimated iron stores (below "0" mg/kg stores) was correlated with the development of anemia at a plasma ferritin value of 10 ng/mL. These analyses provide quantitative data on changes in estimated total body iron for a broad spectrum of blood donors. In contrast to using ferritin alone, this model allows assessment of the iron content of red blood cells and the degree of both iron surplus and depletion over time. © 2017 AABB.

  3. Iron in Alzheimer's and Control Hippocampi - Moessbauer, Atomic Absorption and ELISA Studies

    International Nuclear Information System (INIS)

    Galazka-Friedman, J.; Szlachta, K.; Bauminger, E.R.; Koziorowski, D.; Friedman, A.; Tomasiuk, R.; Jaklewicz, A.; Wszolek, Z.K.; Dickson, D.; Kaplinska, K.

    2011-01-01

    Alzheimer disease is a neurodegenerative process of unknown mechanism taking place in a part of the brain - hippocampus. Oxidative stress and the role of iron in it is one of the suggested mechanisms of cells death. In this study several methods were used to assess iron and iron binding compounds in human hippocampus tissues. Moessbauer spectroscopy was used for identification of the iron binding compound and determination of total iron concentration in 12 control and one Alzheimer disease sample of hippocampus. Moessbauer parameters obtained for all samples suggest that most of the iron is ferritin-like iron. The average concentration of iron determined by Moessbauer spectroscopy in control hippocampus was 45 ± 10 ng/mg wet tissue. The average concentration of iron in 10 Alzheimer disease samples determined by atomic absorption was 66 ± 13 ng/mg wet tissue. The concentration of H and L chains of ferritin in 20 control and 10 AD hippocampi was assessed with enzyme-linked immuno-absorbent assay. The concentration of H and L ferritin was higher in Alzheimer disease compared to control (19.36 ± 1.51 vs. 5.84 ± 0.55 ng/μg protein for H, and 1.39 ± 0.25 vs. 0.55 ± 0.10 for L). This 3-fold increase of the concentration of ferritin is accompanied by a small increase of the total iron concentration. (authors)

  4. Adiposity in women and children from transition countries predicts decreased iron absorption, iron deficiency and a reduced response to iron fortification

    NARCIS (Netherlands)

    Zimmermann, M.B.; Zeder, C.; Muthayya, S.; Winichagoon, P.; Chaouki, N.; Aeberli, I.; Hurrell, R.F.

    2008-01-01

    Background: Overweight is increasing in transition countries, while iron deficiency remains common. In industrialized countries, greater adiposity increases risk of iron deficiency. Higher hepcidin levels in obesity may reduce dietary iron absorption. Therefore, we investigated the association

  5. Iron and zinc absorption from weaning foods prepared from germinated cereals and legumes using isotope tracers

    Energy Technology Data Exchange (ETDEWEB)

    Valdez, D H; Kuizon, M D; Marero, L M; Mallillin, A C; Cruz, E M; Madriaga, J R [Department of Science and Technology, Manila (Philippines). Food and Nutrition Research Inst.

    1994-12-31

    Iron bioavailability from weaning foods prepared from 70:30 combination of germinated rice:mungbean (GRM); germinated rice: cowpea (GRC) and germinated corn:mungbean (GCM) was determined by radioisotopic measurements of iron absorption in human subjects. The gruels were prepared as plain with sugar and flavoring labeled by the extrinsic tag method, and served as hot porridge. It was estimated that iron-deficient infants would absorb 3.5% from GRM, 4.9% from GRC and 5.6% from GCM. Differences between absorption among the weaning foods were not statistically significant. Planning of diets for these age group should include other sources of iron especially heme. Zinc absorption from the weaning food formulations will be studied by the in vitro and in vivo methods. For the in vivo method on human subjects, the absorption of zinc will be determined from the measurement of the whole body retention of the isotope 14 days after intake of the labeled mean. Serum zinc level will be determined to assess the zinc status of the subjects. (author). 23 refs, 1 fig., 4 tabs.

  6. Iron and zinc absorption from weaning foods prepared from germinated cereals and legumes using isotope tracers

    International Nuclear Information System (INIS)

    Valdez, D.H.; Kuizon, M.D.; Marero, L.M.; Mallillin, A.C.; Cruz, E.M.; Madriaga, J.R.

    1994-01-01

    Iron bioavailability from weaning foods prepared from 70:30 combination of germinated rice:mungbean (GRM); germinated rice: cowpea (GRC) and germinated corn:mungbean (GCM) was determined by radioisotopic measurements of iron absorption in human subjects. The gruels were prepared as plain with sugar and flavoring labeled by the extrinsic tag method, and served as hot porridge. It was estimated that iron-deficient infants would absorb 3.5% from GRM, 4.9% from GRC and 5.6% from GCM. Differences between absorption among the weaning foods were not statistically significant. Planning of diets for these age group should include other sources of iron especially heme. Zinc absorption from the weaning food formulations will be studied by the in vitro and in vivo methods. For the in vivo method on human subjects, the absorption of zinc will be determined from the measurement of the whole body retention of the isotope 14 days after intake of the labeled mean. Serum zinc level will be determined to assess the zinc status of the subjects. (author). 23 refs, 1 fig., 4 tabs

  7. Microanalysis of iron oxidation state in iron oxides using X Ray Absorption Near Edge Structure (XANES)

    Science.gov (United States)

    Sutton, S. R.; Delaney, J.; Bajt, S.; Rivers, M. L.; Smith, J. V.

    1993-01-01

    An exploratory application of x ray absorption near edge structure (XANES) analysis using the synchrotron x ray microprobe was undertaken to obtain Fe XANES spectra on individual sub-millimeter grains in conventional polished sections. The experiments concentrated on determinations of Fe valence in a suite of iron oxide minerals for which independent estimates of the iron speciation could be made by electron microprobe analysis and x ray diffraction.

  8. Effect of iron status on iron absorption in different habitual meals in young south Indian women

    Directory of Open Access Journals (Sweden)

    Suneeta Kalasuramath

    2013-01-01

    Full Text Available Background & objectives: Iron deficiency (ID affects a large number of women in India. An inverse relationship exists between iron (Fe status and Fe absorption. Dietary inhibitory and enhancing factors exert a profound influence on bioavailability of Fe. Although the current recommended dietary allowance (RDA for Fe is based on 8 per cent bioavailability, it is not clear if this holds good for the usual highly inhibitory Indian diet matrix. This study was aimed to determine Fe absorption from several habitually consumed south Indian food and to evaluate the interaction of Fe status with absorption. Methods: Four Fe absorption studies were performed on 60 apparently healthy young women, aged 18-35 years. Based on blood biochemistry, 45 of them were ID and 15 were iron replete (IR. The habitual meals assessed were rice, millet and wheat based meals in the ID subjects and rice based meal alone in the IR subjects. Each subject received the test meal labelled with 3 mg of [57] Fe and Fe absorption was measured based on erythrocyte incorporation of isotope label 14 days following administration. Results: Mean fractional Fe absorption from the rice, wheat and millet based meals in the ID subjects were 8.3, 11.2 and 4.6 per cent, respectively. Fe absorption from the rice-based meals was 2.5 per cent in IR subjects. Interpretation & conclusions: Fe absorption is dictated by Fe status from low bioavailability meals. Millet based meals have the lowest bioavailability, while the rice and wheat based meals had moderate to good bioavailability. In millet based meals, it is prudent to consider ways to improve Fe absorption.

  9. Influence of iron on plutonium absorption by the adult and neonatal rat

    International Nuclear Information System (INIS)

    Sullivan, M.F.; Ruemmler, P.S.; Buschbom, R.L.

    1986-01-01

    To determine how iron affects plutonium absorption, adult rats were gavaged with 238 Pu nitrate (pH 2) after they had been fed an iron-deficient diet or treated with iron supplements. Neonatal rats born to dams on an iron-deficient diet were also gavaged with 238 Pu. An iron-deficient diet resulted in enhanced 238 Pu absorption both in the adults and in neonates born to iron-deficient dams. Ferric iron increased 238 Pu absorption 12-fold in adult rats; injected iron-dextran reduced that increase; gavaged ferrous iron reduced 238 Pu absorption to one-third of the control value. Rat neonates absorbed 30 to 40 times as much 238 Pu as adults; absorption was lowered in groups that received iron supplements: Iron-dextran caused a 50% reduction; ferric iron, 95%; and ferrous iron, greater than 95%. The results demonstrate an effect of the oxidation state of iron on plutonium absorption in adult rats different from that observed in suckling rats. The results suggest that the high rate of 238 Pu absorption by neonatal animals is due not only to the permeability of their intestines but also to their high demand for iron

  10. Epigallocatechin gallate (EGCG) (TEAVIGO™) does not impair nonhaem-iron absorption in man

    NARCIS (Netherlands)

    Ullmann, U.; Haller, J.; Bakker, G.C.M.; Brink, E.J.; Weber, P.

    2005-01-01

    A number of studies have shown that tea catechins can inhibit intestinal iron absorption, mostly iron in the nonhaem form. This randomized, double-blind, placebo-controlled, 3-periods cross-over study examined the degree of inhibition of nonhaem iron absorption by pure crystalline epigallocatechin

  11. Iron oxides in human spleen.

    Science.gov (United States)

    Kopáni, Martin; Miglierini, Marcel; Lančok, Adriana; Dekan, Július; Čaplovicová, Mária; Jakubovský, Ján; Boča, Roman; Mrazova, Hedviga

    2015-10-01

    Iron is an essential element for fundamental cell functions and a catalyst for chemical reactions. Three samples extracted from the human spleen were investigated by scanning (SEM) and transmission electron microscopy (TEM), Mössbauer spectrometry (MS), and SQUID magnetometry. The sample with diagnosis of hemosiderosis (H) differs from that referring to hereditary spherocytosis and the reference sample. SEM reveals iron-rich micrometer-sized aggregate of various structures-tiny fibrils in hereditary spherocytosis sample and no fibrils in hemochromatosis. Hematite and magnetite particles from 2 to 6 μm in TEM with diffraction in all samples were shown. The SQUID magnetometry shows different amount of diamagnetic, paramagnetic and ferrimagnetic structures in the tissues. The MS results indicate contribution of ferromagnetically split sextets for all investigated samples. Their occurrence indicates that at least part of the sample is magnetically ordered below the critical temperature. The iron accumulation process is different in hereditary spherocytosis and hemosiderosis. This fact may be the reason of different iron crystallization.

  12. Determination of iron absorption and excretion by whole-body counting

    International Nuclear Information System (INIS)

    Hollard, D.; Benabid, Y.; Berard, M.; Bonnin, J.; Darnault, J.; Millet, M.

    1969-01-01

    Using a whole-body counter, the authors have studied 59 Fe absorption and loss in 8 normal subjects and in 30 iron deficient patients. Results showed that whole-body counting provided an excellent and simple method for iron retention measurements, obviating many inaccuracies of previous technic. Normal absorption of radio iron with this procedure has ranged from 9 per cent to 20 per cent of the administered tracer in normal subjects, with a mean of 15 per cent. A significant increase in 59 Fe absorption was noted in 21 iron-deficient patients in whom the retention ranged from 40 to 100 per cent. However, 3 iron-deficient patients were found to have low absorption, and their severe iron deficiency could be correlated with this defect in absorption. This method permits also the determination of the rate of iron excretion during the following months and therefore the study of the mechanism of some pathological loss. (authors) [fr

  13. Studies on iron absorption and retention in malnourished Indian subjects, using Fe-59 and whole-body counting

    International Nuclear Information System (INIS)

    Gopalan, C.; Srikantia, S.G.

    1975-12-01

    The gastrointestinal absorption of iron under various conditions in representatives of the Indian population, and several related matters, have been investigated. Percentage absorption was determined by whole-body counting of 59Fe, or by measuring the concentration of 55Fe in the blood, at about two weeks after administration of the respective tracer. It was confirmed or established that: (1) food or supplemental iron, if available at all, tends to be absorbed from the intestines as if present there in one of two alternative pools: heme and non heme; (2) 30%-50% of iron measured chemically in Indian foods appears to be in an unavailable form, for example as a contaminant in adventitiously present dust; (3) fortification of the diet with iron may be feasible by adding FePO 4 + 2 molar NaHSO 4 to common salt under suitable conditions; (4) monkeys appear to be sufficiently similar to humans in their iron absorption characteristics that they may be the best available non-human model for preliminary experimental investigations of iron absorption; and (5) a promising preparative method for liquid scintillation counting of 55Fe present in blood is to extract it into toluene in the presence of di (2-ethyl-hexyl) phosphate (HDEHP)

  14. A preliminary study of iron absorption by whole body counting and correlation with DFO excretion

    International Nuclear Information System (INIS)

    Gupta, M.M.; Bhattacharyya, L.; Gupta, N.K.; Bhola, G.C.; Nagaratnam, A.; Manchanda, R.; Bhargva, M.; Kumar, S.

    1975-01-01

    A preliminary study of iron absorption by oral administration of 59 Fe and whole body counting was carried on a group of 16 women. The cases included 8 patients suffering from iron deficiency anaemia and various infections as well as 8 healthy controls. High iron absorption is associated with iron deficiency, these changes being more marked in iron deficient controls than in those with infection or malignancy. In iron deficient controls results of whole body counting correlate very well with other haematological investigations. (orig.) [de

  15. Experimental study of absorption of iron in foods using whole-body counter

    International Nuclear Information System (INIS)

    Nakamura, Tadamitsu

    1978-01-01

    Male rats of Wistar strain which showed normal hematological picture were given 59 Fe-labeled foods orally, and the iron absorption rate was determined by an animal whole body counter. When 59 Fe was given in a mixture with each of gruel, spinach, cow's milk, the yolk, and the yolk with orange juice, the iron absorption rates in each food were 9.4%, 8.9%, 6.6%, 10.8% and 7.2% respectively. None of these foods seemed to inhibit the 59 Fe absorption. When 59 Fe was given in a mixture with chicken, the iron absorption rate was 35.8%. This result suggested that the chicken promoted the 59 Fe absorption. When the yolk labeled in vivo with 59 Fe was given, the iron absorption rate was 4.9%. If the yolk labeled in vitro was used, the absorption rate was 10.8%. When the yolk labeled in vivo with 59 Fe was given with orange juice, the iron absorption rate was 13.3%. If the yolk labeled in vivo with 59 Fe was given, the absorption rate was 7.2%. Orange juice had no effect on the iron absorption when the yolk labeled in vitro was used. After chicken eggs labeled in vivo with 59 Fe was given to children, the iron absorption was determined by a whole body counter; the rate averaged 5.4 in the children without anemia and 24.7 in those with anemia. (Ueda, J.)

  16. Phytosterol glycosides reduce cholesterol absorption in humans

    OpenAIRE

    Lin, Xiaobo; Ma, Lina; Racette, Susan B.; Anderson Spearie, Catherine L.; Ostlund, Richard E.

    2009-01-01

    Dietary phytosterols inhibit intestinal cholesterol absorption and regulate whole body cholesterol excretion and balance. However, they are biochemically heterogeneous and a portion is glycosylated in some foods with unknown effects on biological activity. We tested the hypothesis that phytosterol glycosides reduce cholesterol absorption in humans. Phytosterol glycosides were extracted and purified from soy lecithin in a novel two-step process. Cholesterol absorption was measured in a series ...

  17. Iron absorption by roots of fruit plants : some characteristics of the phenomena

    International Nuclear Information System (INIS)

    Bindra, A.S.

    1979-01-01

    Using young plants of peach, plum and almond growing in water culture, study was undertaken on the absorption and translocation of labelled iron. When peach plants deficient in this element were supplied with it, they tended to absorb it very rapidly, especially during the first 30 minutes. This absorption was not a superficial adsorption. Iron absorption was found to be linked to the length of non-lignified roots. Of the three species, almond absorbed more iron than peach but less than olum. No significant varietal difference was found regarding the iron absorption capacity of roots of different varieties of peach. Removal of foliage did not influence the absorption of iron by roots of peach plants in the early stages. (auth.)

  18. Dietary inulin supplementation does not promote colonic iron absorption in a porcine model

    Science.gov (United States)

    Prebiotics may enhance iron bioavailability by increasing iron absorption in the colon. Anemic pigs fitted with cecal cannulas were fed a low-iron diet with or without 4% inulin. Over 7 days, pigs were administered 1 mg 54 Fe in the morning feed followed by cannula infusion of 0.5 mg 58 Fe to measu...

  19. Studies on the absorption of iron after oral administration in piglets

    International Nuclear Information System (INIS)

    Thoren-Tolling, K.

    1975-01-01

    72 newborn piglets from 9 litters were used to determinate the retention and distribution in the body of labelled iron given either orally as ferrous fumarate (100 mg Fe 2+ ) or iron dextran (200 mg Fe 3+ ), or by injection as iron dextran (100 mg Fe 3+ ). About 25-30 % of the radioiron from a single oral dose of labelled ferrous fumarate (100 mg Fe 2+ ), and about 55-60 % from a single oral dose of labelled iron dextran (200 mg Fe 3+ ) were absorbed by the body. As iron is excreted throughout the experiment, only about 20% and 40-50% respectively of the radio-iron from these iron compounds were recovered 3 weeks after treatment. The total amounts of labelled iron retained in the body after oral administration of the same doses of these iron compounds, alone or in combination, were compared. A slight retardation of the absorption of ferrous iron was observed when iron dextran was administered simultaneeously. The absorption of iron dextran was not influenced by the simultaneous administration of ferrous fumarate. The importance of the liver as the main iron storage site was shown, and the rapid utilization of iron from storage sites, about 2-3 weeks after treatment was demonstrated. The concentration of labelled iron in urine and some lymphglands was measured. Only minute quantities of radio-iron were excreted in the urine throughout the entire experiment. The lymph nodes seem to act as iron stones after administration of iron dextran. The importance of the lymphatic tissue in absorption and storage of labelled iron is discussed. (author)

  20. The influence of high iron diet on rat lung manganese absorption

    International Nuclear Information System (INIS)

    Thompson, Khristy; Molina, Ramon; Donaghey, Thomas; Brain, Joseph D.; Wessling-Resnick, Marianne

    2006-01-01

    Individuals chronically exposed to manganese are at high risk for neurotoxic effects of this metal. A primary route of exposure is through respiration, although little is known about pulmonary uptake of metals or factors that modify this process. High dietary iron levels inversely affect intestinal uptake of manganese, and a major goal of this study was to determine if dietary iron loading could increase lung non-heme iron levels and alter manganese absorption. Rats were fed a high iron (1% carbonyl iron) or control diet for 4 weeks. Lung non-heme iron levels increased ∼2-fold in rats fed the high iron diet. To determine if iron-loading affected manganese uptake, 54 Mn was administered by intratracheal (it) instillation or intravenous (iv) injection for pharmacokinetic studies. 54 Mn absorption from the lungs to the blood was lower in it-instilled rats fed the 1% carbonyl iron diet. Pharmacokinetics of iv-injected 54 Mn revealed that the isotope was cleared more rapidly from the blood of iron-loaded rats. In situ analysis of divalent metal transporter-1 (DMT1) expression in lung detected mRNA in airway epithelium and bronchus-associated lymphatic tissue (BALT). Staining of the latter was significantly reduced in rats fed the high iron diet. In situ analysis of transferrin receptor (TfR) mRNA showed staining in BALT alone. These data demonstrate that manganese absorption from the lungs to the blood can be modified by iron status and the route of administration

  1. Serum-ferritin and iron absorption for the study of body iron stored in the Thai population

    International Nuclear Information System (INIS)

    Plehachinda, R.

    1984-05-01

    Measurements of serum ferritin by an ''in-house'' immunoradiometric assay (IRMA) method were used in conjunction with estimations of gastro-intestinal iron absorption from a standard test dose of ferrous ascorbate, measurements of blood haemoglobin and measurements of other haematological parameters to study body iron status in various population groups and to assess changes in body iron status after food-iron fortification. The IRMA method particularly covered the lower range of serum ferritin levels from 0.5 to 10 μg/litre, corresponding to iron deficiency. Quality control indicated satisfactory assay performance. In preliminary studies, serum ferritin level was found to be well correlated with gastro-intestinal iron absorption as an indicator of body iron status. Normal adult male subjects in Bangkok showed levels of 21-314 μg/litre and normal adult female levels of 13-173 μg/litre, in general agreement with values reported by other authors. Measurements were then extended to subjects in an area of north-eastern Thailand where iron-deficiency was common, to assess the effectiveness of food-iron fortification programmes. Measurements were also made on male blood donors in Bangkok, pregnant female subjects in Bangkok and north-eastern Thailand, school children in an area of southern Thailand where hookworm infestation was common and schoolchildren and adult female subjects in an area of northern Thailand where goitre was endemic. The results of all these studies are presented

  2. Molecular absorption spectra of beryllium, cerium, lanthanum, iron, and platinum salts

    International Nuclear Information System (INIS)

    Daidoji, Hidehiro

    1980-01-01

    The absorption spectra of some salts of beryllium, cerium, lanthanum, iron and platinum in air-acetylene flame were measured in the wavelength range from 200 to 400 nm. A Hitachi 207 type atomic absorption spectrophotometer was used. A deuterium lamp, a home-made continuous radiation lamp and some hollow cathode lamps were used as light sources. The new molecular absorption spectra of cerium, lanthanum and platinum and the absorption spectra due to Be(OH) 2 , LaO, PtH, FeO and FeCl in 200-400 nm region were obtained. Emission spectra of CeO, LaO and FeOH were also obtained. These molecular absorption bands were estimated as absorption errors of maximum 15 times to the sensitivity of each elements in atomic absorption spectrometry. In addition, spectral line interferences of iron were observed in atomic absorption spectrometry of Zn, Cd, Ni, Cu and Cr. (author)

  3. [Iron absorption of the habitual diet in a population of low socioeconomic level].

    Science.gov (United States)

    Morón, C; Kremenchuzky, S; Passamai, M I; D'Andrea de Rivero, S; Pérez de Galíndez, G; Gerschcovich, C

    1985-06-01

    Iron absorption using the extrinsic double-tag method was determined in the habitual diet consumed by a group of 32 volunteers of both sexes, pertaining to the low socioeconomic strata. The diet was made up of bread, spaghetti, vegetables and meat, totalling 2,022 kcal, 65.0 g protein, 17.57 mg iron, and 28.75 mg ascorbic acid. According to our findings, men were found to be neither anemic nor iron-deficient. Among the women, however, 4.8% had anemia and 57.1% suffered from iron deficiency. The non-heme iron absorption was very low: 1.35% at breakfast, 3.29% at lunch, and 3.82% at dinner. Among those subjects found to be normal, the absorption was half the above figures, whereas among those with iron deficiency it was threefold, the differences being highly significant. The absorption of heme-iron for lunch and dinner was 17.53%. The iron deficient group had an absorption value four times greater than the normal group, the differences also being highly significant. The daily availability of non-heme, heme and total iron was 0.44, 1.13 and 1.57 mg, respectively. In the subjects who formed the normal group, total iron available was 1.14 mg, barely covering a man's daily requirements, but not those of a woman. In the iron-deficient group, it was 4.31 mg, that is, four times greater than in the normal group; while this value improves the balance, it does not prevent deficiency in women, with great blood losses. Bearing these results in mind, it is suggested that measures tending to improve dietary iron content and bio-availability, be enforced.

  4. Diagnostic relevance of radioiron-absorption-measurements and immunoradiometric serum-ferritin-assay in the evaluation of iron stores

    International Nuclear Information System (INIS)

    Heinrich, H.C.

    1978-01-01

    Negative iron balance and enhanced iron demand respectively causes deficient iron stores (prelatent iron deficiency) with increased iron absorption, later on decrease of serum iron and increase of transferrin (latent Fe deficiency) and at least iron deficient anemia (manifest iron deficiency). In prelatend iron deficiency diagnostic 59 Fe 2+ absorption is increased and the RES cells do not show storage iron cytochemically. In latent iron deficiency in addition serum iron, transferrin iron saturation and serum ferritin is decreased and hypochromic mikrocytic anemia completes the signs of manifest iron deficiency. Besides rare cases of primary hemochromatosis and marked hyperdasia of ineffective erythropoiesis in homocygotic beta-thalassemia, hereditary non-spherocytic hemolytic anemia caused by pyruvate kinase deficiency and some sideroblastic anemias increased 59 Fe 2+ absorption is a reliable measure of exhausted iron stores. In these exceptional cases differential diagnosis between sideroachrestic and siderosensitive iron deficiency anemia can be made by measurement of serum iron and serum ferritin respectively. The etiology of iron deficiency is to be cleared by measurement of 59 Fe absorption from 59 Fe 2+ and 59 Fe-marked meat with consecutive estimation of whole body 59 Fe elimination. Shortly after completion or during oral iron therapy serum ferritin concentration is not suitable to evaluate the content of iron stores. (orig.) [de

  5. Iron and zinc absorption from weaning foods prepared from germinated cereals and legumes

    International Nuclear Information System (INIS)

    Kuizon, M.D.

    1992-01-01

    Iron deficiency anaemia is a public health problem in the Philippines especially in infants, children and pregnant women. The immediate cause is inadequate intake of available iron to meet increased iron requirements. Iron supplementation studies on pregnant women showed improvement in haemoglobin level and reduction of prevalence of anaemia. A project on iron fortification of rice with ferrous sulphate is going on. It is proposed to study iron and zinc absorption from weaning food prepared from germinated rice: mungbean, germinated rice: cowpea, and germinated corn:mungbean to support the finding that these formulations will alleviate not only protein-energy malnutrition but contribute to improvement of iron status as well since iron contents are higher and anti-nutritional factors (phytates and tannin) are either reduced or eliminated. This study aims to measure the iron and zinc absorption from weaning foods prepared from germinated rice-mungbean, germinated rice-cowpea, and germinated corn-mungbean and to indicate usefullness of modifying local foods to improve iron absorption. 24 refs, 4 figs

  6. Iron oxides in human brain

    International Nuclear Information System (INIS)

    Cesnek, M.; Miglierini, M.; Lancok, A.

    2015-01-01

    It was confirmed that Moessbauer spectroscopy is an useful tool for measurement of biological tissues even if the concentration of iron in the samples is very low. Moessbauer spectra revealed a presence of particles with non-magnetic behaviour at room temperature. At temperature 4.2 K almost all particles exhibit magnetic behaviour. The rest of the particles still exhibits superparamagnetic behaviour what indicates that their blocking temperature is lower than 4.2 K. It was suggested that those might be very small haemosiderin particles. Parameters the sextet-like components suggest possible presence of goethite, akaganeit or ferrihydrite. Using synchrotron assisted XRD, it was not possible to reveal any iron relevant structural information due to very low concentration of iron atoms in samples. Atomic pairs with the highest contribution to PDF were revealed. All these atomic pairs are characteristic for biological materials. XRD measurement of extracted ferritin could reveal some helpful information about the iron structure. (authors)

  7. Effect of tannic acid on iron absorption in straw-colored fruit bats(Eidolon helvum)

    Science.gov (United States)

    Excessive absorption and subsequent storage of dietary iron has been found in a variety of captively held birds and mammals, including fruit bats. It is thought that feeding a diet that is low in iron can prevent the onset of this disease; however, manufacturing a diet with commonly available foodst...

  8. The effects of fat loss after bariatric surgery on inflammation, serum hepcidin, and iron absorption

    NARCIS (Netherlands)

    Cepeda-Lopez, Ana C.; Allende-Labastida, Javier; Melse-Boonstra, Alida; Osendarp, Saskia J.M.; Herter-Aeberli, Isabelle; Moretti, Diego; Rodriguez-Lastra, Ramiro; Gonzalez-Salazar, Francisco; Villalpando, Salvador; Zimmermann, Michael B.

    2016-01-01

    Background: Iron deficiency is common in obese subjects. This may be due to an increase in serum hepcidin and a decrease in iron absorption from adiposity-related inflammation. Objective: We evaluated whether weight and fat loss in obese subjects would decrease inflammation and serum hepcidin and

  9. Phytosterol glycosides reduce cholesterol absorption in humans

    Science.gov (United States)

    Lin, Xiaobo; Ma, Lina; Racette, Susan B.; Anderson Spearie, Catherine L.; Ostlund, Richard E.

    2009-01-01

    Dietary phytosterols inhibit intestinal cholesterol absorption and regulate whole body cholesterol excretion and balance. However, they are biochemically heterogeneous and a portion is glycosylated in some foods with unknown effects on biological activity. We tested the hypothesis that phytosterol glycosides reduce cholesterol absorption in humans. Phytosterol glycosides were extracted and purified from soy lecithin in a novel two-step process. Cholesterol absorption was measured in a series of three single-meal tests given at intervals of 2 wk to each of 11 healthy subjects. In a randomized crossover design, participants received ∼300 mg of added phytosterols in the form of phytosterol glycosides or phytosterol esters, or placebo in a test breakfast also containing 30 mg cholesterol-d7. Cholesterol absorption was estimated by mass spectrometry of plasma cholesterol-d7 enrichment 4–5 days after each test. Compared with the placebo test, phytosterol glycosides reduced cholesterol absorption by 37.6 ± 4.8% (P lecithin are bioactive in humans and should be included in methods of phytosterol analysis and tables of food phytosterol content. PMID:19246636

  10. Phytosterol glycosides reduce cholesterol absorption in humans.

    Science.gov (United States)

    Lin, Xiaobo; Ma, Lina; Racette, Susan B; Anderson Spearie, Catherine L; Ostlund, Richard E

    2009-04-01

    Dietary phytosterols inhibit intestinal cholesterol absorption and regulate whole body cholesterol excretion and balance. However, they are biochemically heterogeneous and a portion is glycosylated in some foods with unknown effects on biological activity. We tested the hypothesis that phytosterol glycosides reduce cholesterol absorption in humans. Phytosterol glycosides were extracted and purified from soy lecithin in a novel two-step process. Cholesterol absorption was measured in a series of three single-meal tests given at intervals of 2 wk to each of 11 healthy subjects. In a randomized crossover design, participants received approximately 300 mg of added phytosterols in the form of phytosterol glycosides or phytosterol esters, or placebo in a test breakfast also containing 30 mg cholesterol-d7. Cholesterol absorption was estimated by mass spectrometry of plasma cholesterol-d7 enrichment 4-5 days after each test. Compared with the placebo test, phytosterol glycosides reduced cholesterol absorption by 37.6+/-4.8% (Pphytosterol esters 30.6+/-3.9% (P=0.0001). These results suggest that natural phytosterol glycosides purified from lecithin are bioactive in humans and should be included in methods of phytosterol analysis and tables of food phytosterol content.

  11. The Relationship Between Intestinal Iron Absorption and Hepatic Parenchymal Cell Damage

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mok Hyun; Hahn, Shin Suck [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1971-09-15

    Since the iron balance is maintained by regulated intestinal absorption rather than regulated excretion, there have been many reports concerning the factors which may influence the intestinal iron absorption. As the liver is the largest iron storage organ of the body, any hepatocellular damage may result in disturbances in iron metabolism, e,g., frequent co-existence of haemochromatosis and liver cirrhosis, or elevated serum iron level and increased iron absorption rate in patients with infectious hepatitis or cirrhosis. In one effort to demonstrate the influence of hepatocellular damage on intestinal iron absorption, the iron absorption rate was measured in the rabbits whose livers were injured by a single subcutaneous injection of carbon tetrachloride (doses ranging from 0.15 to 0.5 cc per kg of body weight) or by a single irradiation of 2, 000 to 16, 000 rads with Co on the liver locally. A single oral dose of 1muCi of Fe-citrate with 0.5 mg of ferrous citrate was fed in the fasting state, 24 hours after hepatic damage had been induced, without any reducing or chelating agents, and stool was collected for one week thereafter. Serum iron levels, together with conventional liver function teats, were measured at 24, 48, 72, 120 and 168 hours after liver damage had been induced. All animals were sacrificed upon the completing of the one week's test period and tissue specimens were prepared for H-E and Gomori's iron stain. Following are the results. 1. Normal iron absorption rate of the rabbit was 41.72+-3.61% when 0.5 mg of iron was given in the fasting state, as measured by subtracting the amount recovered in stool collected for 7 days from the amount given. The test period of 7 days is adequate, for only 1% of the iron given was excreted thereafter. 2. The intestinal iron absorption rate and serum iron level were significantly increased when the animal was poisoned by a single subcutaneous injection of 0.15 cc, per kg. of body weight of carbon tetrachloride or

  12. The Relationship Between Intestinal Iron Absorption and Hepatic Parenchymal Cell Damage

    International Nuclear Information System (INIS)

    Kim, Mok Hyun; Hahn, Shin Suck

    1971-01-01

    Since the iron balance is maintained by regulated intestinal absorption rather than regulated excretion, there have been many reports concerning the factors which may influence the intestinal iron absorption. As the liver is the largest iron storage organ of the body, any hepatocellular damage may result in disturbances in iron metabolism, e,g., frequent co-existence of haemochromatosis and liver cirrhosis, or elevated serum iron level and increased iron absorption rate in patients with infectious hepatitis or cirrhosis. In one effort to demonstrate the influence of hepatocellular damage on intestinal iron absorption, the iron absorption rate was measured in the rabbits whose livers were injured by a single subcutaneous injection of carbon tetrachloride (doses ranging from 0.15 to 0.5 cc per kg of body weight) or by a single irradiation of 2, 000 to 16, 000 rads with Co on the liver locally. A single oral dose of 1μCi of Fe-citrate with 0.5 mg of ferrous citrate was fed in the fasting state, 24 hours after hepatic damage had been induced, without any reducing or chelating agents, and stool was collected for one week thereafter. Serum iron levels, together with conventional liver function teats, were measured at 24, 48, 72, 120 and 168 hours after liver damage had been induced. All animals were sacrificed upon the completing of the one week's test period and tissue specimens were prepared for H-E and Gomori's iron stain. Following are the results. 1. Normal iron absorption rate of the rabbit was 41.72±3.61% when 0.5 mg of iron was given in the fasting state, as measured by subtracting the amount recovered in stool collected for 7 days from the amount given. The test period of 7 days is adequate, for only 1% of the iron given was excreted thereafter. 2. The intestinal iron absorption rate and serum iron level were significantly increased when the animal was poisoned by a single subcutaneous injection of 0.15 cc, per kg. of body weight of carbon tetrachloride or

  13. Effect of sodium iron ethylenediaminetetraacetic acid on the absorption of various trace elements in anemic rats

    International Nuclear Information System (INIS)

    Igarashi, Kaori; Sasaki, Ayako; Yoda, Yoko; Inage, Hiroko; Nakanishi, Yukiko; Kimura, Shuichi; Yanagiya, Takahiro; Hirunuma, Rieko; Enomoto, Shuichi

    2001-01-01

    Iron deficiency in developing countries is attributed to the bioavailability of iron derived from staple food such as grains, vegetables and legumes. Sodium iron ethylenediaminetetraacetic acid (NaFeEDTA), a strong metal chelator, is one of the food additives for iron fortification and it has been for improvement of iron deficiency in the world. However, the effect of NaFeEDTA on the absorption of trace elements other than Fe has been poorly understood. In the present study, to investigate the effect of NaFeEDTA on the absorption of trace elements, we determined the uptake rate of various metals using a multitracer technique. The uptake rates of Zn, Co, and Na in rats fed with NaFeEDTA diet were significantly lower than those in rats fed with ferrous sulfate (FS) diet, suggesting that iron fortification by NaFeEDTA lowers the bioavailability of various elements compared with FS. On the other hand, iron fortification using the FS diet in the presence of tannic acid decreased the bioavailability of Zn and Rb. However, no effect of tannic acid on the uptake rate of metal was observed in NaFeEDTA diet, suggesting that iron fortification using NaFeEDTA is less affected by tannic acid than that using the FS diet. These results indicate that iron fortification using NaFeEDTA is an effective method for improving iron deficiency. (author)

  14. X-ray absorption spectroscopic studies of mononuclear non-heme iron enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Westre, Tami E. [Stanford Univ., CA (United States)

    1996-01-01

    Fe-K-edge X-ray absorption spectroscopy (XAS) has been used to investigate the electronic and geometric structure of the iron active site in non-heme iron enzymes. A new theoretical extended X-ray absorption fine structure (EXAFS) analysis approach, called GNXAS, has been tested on data for iron model complexes to evaluate the utility and reliability of this new technique, especially with respect to the effects of multiple-scattering. In addition, a detailed analysis of the 1s→3d pre-edge feature has been developed as a tool for investigating the oxidation state, spin state, and geometry of iron sites. Edge and EXAFS analyses have then been applied to the study of non-heme iron enzyme active sites.

  15. Alpha-lactalbumin and casein-glycomacropeptide do not affect iron absorption from formula in healthy term infants

    Science.gov (United States)

    Iron absorption from infant formula is relatively low. Alpha-lactalbumin and casein-glycomacropeptide have been suggested to enhance mineral absorption. We therefore assessed the effect of alpha-lactalbumin and casein-glycomacropeptide on iron absorption from infant formula in healthy term infants. ...

  16. Absorption of manganese and iron in a mouse model of hemochromatosis.

    Directory of Open Access Journals (Sweden)

    Jonghan Kim

    Full Text Available Hereditary hemochromatosis, an iron overload disease associated with excessive intestinal iron absorption, is commonly caused by loss of HFE gene function. Both iron and manganese absorption are regulated by iron status, but the relationships between the transport pathways of these metals and how they are affected by HFE-associated hemochromatosis remain poorly understood. Loss of HFE function is known to alter the intestinal expression of DMT1 (divalent metal transporter-1 and Fpn (ferroportin, transporters that have been implicated in absorption of both iron and manganese. Although the influence of HFE deficiency on dietary iron absorption has been characterized, potential effects on manganese metabolism have yet to be explored. To investigate the role of HFE in manganese absorption, we characterized the uptake and distribution of the metal in Hfe (-/- knockout mice after intravenous, intragastric, and intranasal administration of (54Mn. These values were compared to intravenous and intragastric administration of (59Fe. Intestinal absorption of (59Fe was increased and clearance of injected (59Fe was also increased in Hfe(-/- mice compared to controls. Hfe (-/- mice displayed greater intestinal absorption of (54Mn compared to wild-type Hfe(+/+ control mice. After intravenous injection, the distribution of (59Fe to heart and liver was greater in Hfe (-/- mice but no remarkable differences were observed for (54Mn. Although olfactory absorption of (54Mn into blood was unchanged in Hfe (-/- mice, higher levels of intranasally-instilled (54Mn were associated with Hfe(-/- brain compared to controls. These results show that manganese transport and metabolism can be modified by HFE deficiency.

  17. Absorption of Manganese and Iron in a Mouse Model of Hemochromatosis

    Science.gov (United States)

    Kim, Jonghan; Buckett, Peter D.; Wessling-Resnick, Marianne

    2013-01-01

    Hereditary hemochromatosis, an iron overload disease associated with excessive intestinal iron absorption, is commonly caused by loss of HFE gene function. Both iron and manganese absorption are regulated by iron status, but the relationships between the transport pathways of these metals and how they are affected by HFE-associated hemochromatosis remain poorly understood. Loss of HFE function is known to alter the intestinal expression of DMT1 (divalent metal transporter-1) and Fpn (ferroportin), transporters that have been implicated in absorption of both iron and manganese. Although the influence of HFE deficiency on dietary iron absorption has been characterized, potential effects on manganese metabolism have yet to be explored. To investigate the role of HFE in manganese absorption, we characterized the uptake and distribution of the metal in Hfe −/− knockout mice after intravenous, intragastric, and intranasal administration of 54Mn. These values were compared to intravenous and intragastric administration of 59Fe. Intestinal absorption of 59Fe was increased and clearance of injected 59Fe was also increased in Hfe−/− mice compared to controls. Hfe −/− mice displayed greater intestinal absorption of 54Mn compared to wild-type Hfe+/+ control mice. After intravenous injection, the distribution of 59Fe to heart and liver was greater in Hfe −/− mice but no remarkable differences were observed for 54Mn. Although olfactory absorption of 54Mn into blood was unchanged in Hfe −/− mice, higher levels of intranasally-instilled 54Mn were associated with Hfe−/− brain compared to controls. These results show that manganese transport and metabolism can be modified by HFE deficiency. PMID:23705020

  18. Higher iron bioavailability of a human-like collagen iron complex.

    Science.gov (United States)

    Zhu, Chenhui; Yang, Fan; Fan, Daidi; Wang, Ya; Yu, Yuanyuan

    2017-07-01

    Iron deficiency remains a public health problem around the world due to low iron intake and/or bioavailability. FeSO 4 , ferrous succinate, and ferrous glycinate chelate are rich in iron but have poor bioavailability. To solve the problem of iron deficiency, following previous research studies, a thiolated human-like collagen-ironcomplex supplement with a high iron content was prepared in an anaerobic workstation. In addition, cell viability tests were evaluated after conducting an MTT assay, and a quantitative analysis of the thiolated human-like collagen-iron digesta samples was performed using the SDS-PAGE method coupled with gel filtration chromatography. The iron bioavailability was assessed using Caco-2 cell monolayers and iron-deficiency anemia mice models. The results showed that (1) one mole of thiolated human-like collagen-iron possessed approximately 35.34 moles of iron; (2) thiolated human-like collagen-iron did not exhibit cytotoxity and (3) thiolated human-like collagen- iron digesta samples had higher bioavailability than other iron supplements, including FeSO 4 , ferrous succinate, ferrous glycine chelate and thiolated human-like collagen-Fe iron. Finally, the iron bioavailability was significantly enhanced by vitamin C. These results indicated that thiolated human-like collagen-iron is a promising iron supplement for use in the future.

  19. Enhanced microwave absorption in ZnO/carbonyl iron nano-composites by coating dielectric material

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Chang [School of Physics and Material Science, Anhui University, Hefei 230036 (China); Key Laboratory of Opto-electronic Information Acquisition and Manipulation Ministry of Education, Anhui University, Hefei 230039 (China); Fang Qingqing, E-mail: physfangqq@126.com [School of Physics and Material Science, Anhui University, Hefei 230036 (China) and Key Laboratory of Opto-electronic Information Acquisition and Manipulation Ministry of Education, Anhui University, Hefei 230039 (China); Yan Fangliang; Wang Weina; Wu Keyue; Liu Yanmei; Lv Qingrong; Zhang Hanming; Zhang Qiping; Li Jinguang; Ding Qiongqiong [School of Physics and Material Science, Anhui University, Hefei 230036 (China); Key Laboratory of Opto-electronic Information Acquisition and Manipulation Ministry of Education, Anhui University, Hefei 230039 (China)

    2012-05-15

    The microwave absorption properties of zinc oxide/carbonyl iron composite nanoparticles fabricated by high energy ball milling were studied at 0-20 GHz. Experiments showed that ZnO as a kind of dielectric material coating carbonyl iron particles made the bandwidth of reflection loss (RL)<-5 dB expanding to the low frequency, and enhanced absorption effect obviously. For a 3 mm thickness absorber of ZnO/carbonyl iron after 30 h milling, the values of RL<-5 dB and RL<-8 dB were obtained in the frequency range from 7.0 GHz to 17.8 GHz and from 9.8 dB to 14.9 dB, respectively, and its strongest RL peak was -29.34 dB at 13.59 GHz. The magnetic loss of carbonyl iron particles and the dielectric loss of ZnO particles were the main mechanisms of microwave absorption for the composites. - Highlights: Black-Right-Pointing-Pointer We fabricated zinc oxide/carbonyl iron composites by high energy ball milling. Black-Right-Pointing-Pointer ZnO dielectric property increased absorption effect and absorption bandwidth. Black-Right-Pointing-Pointer Absorbing frequence of composites is expanding to low frequency direction. Black-Right-Pointing-Pointer The craft of high energy ball milling is easy to realize commerce production.

  20. Enhanced microwave absorption in ZnO/carbonyl iron nano-composites by coating dielectric material

    International Nuclear Information System (INIS)

    Zhou Chang; Fang Qingqing; Yan Fangliang; Wang Weina; Wu Keyue; Liu Yanmei; Lv Qingrong; Zhang Hanming; Zhang Qiping; Li Jinguang; Ding Qiongqiong

    2012-01-01

    The microwave absorption properties of zinc oxide/carbonyl iron composite nanoparticles fabricated by high energy ball milling were studied at 0–20 GHz. Experiments showed that ZnO as a kind of dielectric material coating carbonyl iron particles made the bandwidth of reflection loss (RL)<−5 dB expanding to the low frequency, and enhanced absorption effect obviously. For a 3 mm thickness absorber of ZnO/carbonyl iron after 30 h milling, the values of RL<−5 dB and RL<−8 dB were obtained in the frequency range from 7.0 GHz to 17.8 GHz and from 9.8 dB to 14.9 dB, respectively, and its strongest RL peak was −29.34 dB at 13.59 GHz. The magnetic loss of carbonyl iron particles and the dielectric loss of ZnO particles were the main mechanisms of microwave absorption for the composites. - Highlights: ► We fabricated zinc oxide/carbonyl iron composites by high energy ball milling. ► ZnO dielectric property increased absorption effect and absorption bandwidth. ► Absorbing frequence of composites is expanding to low frequency direction. ► The craft of high energy ball milling is easy to realize commerce production.

  1. Zinc Absorption from Micronutrient Powder Is Low but Is not Affected by Iron in Kenyan Infants

    Directory of Open Access Journals (Sweden)

    Fabian Esamai

    2014-12-01

    Full Text Available Interference with zinc absorption is a proposed explanation for adverse effects of supplemental iron in iron-replete children in malaria endemic settings. We examined the effects of iron in micronutrient powder (MNP on zinc absorption after three months of home fortification with MNP in maize-based diets in rural Kenyan infants. In a double blind design, six-month-old, non-anemic infants were randomized to MNP containing 5 mg zinc, with or without 12.5 mg of iron (MNP + Fe and MNP − Fe, respectively; a control (C group received placebo powder. After three months, duplicate diet collections and zinc stable isotopes were used to measure intake from MNP + non-breast milk foods and fractional absorption of zinc (FAZ by dual isotope ratio method; total absorbed zinc (TAZ, mg/day was calculated from intake × FAZ. Mean (SEM TAZ was not different between MNP + Fe (n = 10 and MNP − Fe (n = 9 groups: 0.85 (0.22 and 0.72 (0.19, respectively, but both were higher than C (n = 9: 0.24 (0.03 (p = 0.04. Iron in MNP did not significantly alter zinc absorption, but despite intakes over double estimated dietary requirement, both MNP groups’ mean TAZ barely approximated the physiologic requirement for age. Impaired zinc absorption may dictate need for higher zinc doses in vulnerable populations.

  2. Removal of iron interferences by solvent extraction for geochemical analysis by atomic-absorption spectrophotometry

    Science.gov (United States)

    Zhou, L.; Chao, T.T.; Sanzolone, R.F.

    1985-01-01

    Iron is a common interferent in the determination of many elements in geochemical samples. Two approaches for its removal have been taken. The first involves removal of iron by extraction with methyl isobutyl ketone (MIBK) from hydrochloric acid medium, leaving the analytes in the aqueous phase. The second consists of reduction of iron(III) to iron(II) by ascorbic acid to minimize its extraction into MIBK, so that the analytes may be isolated by extraction. Elements of interest can then be determined using the aqueous solution or the organic extract, as appropriate. Operating factors such as the concentration of hydrochloric acid, amounts of iron present, number of extractions, the presence or absence of a salting-out agent, and the optimum ratio of ascorbic acid to iron have been determined. These factors have general applications in geochemical analysis by atomic-absorption spectrophotometry. ?? 1985.

  3. Effects of iron deficiency on the absorption and distribution of lead and cadmium in rats

    International Nuclear Information System (INIS)

    Ragan, H.A.

    1977-01-01

    In order to evaluate the effects of iron deficiency on the absorption of pollutant metals, an iron-deficient diet was fed to young rats until their tissue-iron stores were depleted. Prior to the development of anemia, the iron-deficient rats and littermate controls were administered an intragastric gavage of lead-210 or cadmium-109 and were killed 48 hr later. The body burden of lead was approximately 6 times greater, and that of cadmium approximately 7 times greater, in iron-deficient rats than in the controls. No consistent effects were observed on concentrations of serum total lipids or serum proteins nor on protein electrophoretic patterns in rats with a deficit in iron stores

  4. Acute inhibition of iron bioavailability by zinc: studies in humans.

    Science.gov (United States)

    Olivares, Manuel; Pizarro, Fernando; Ruz, Manuel; de Romaña, Daniel López

    2012-08-01

    Iron (Fe) and zinc (Zn) deficiencies constitute two of the most important nutritional and public health problems affecting developing countries. Combined supplementation or fortification with Zn and Fe are strategies that can be used to improve the Zn and Fe status of a population. However, there is concern about potential negative interactions between these two micronutrients due to a competitive binding to DMT1 and Zip14 transporter. Studies performed in humans have shown an inhibitory effect of Zn on Fe absorption when both minerals are given together as a solution in fasting conditions. We found that at low doses of iron (0.5 mg) the threshold for the inhibition of iron bioavailability was at a Zn:Fe wt/wt ratio ≥5.9:1, whereas at higher doses of Fe (10 mg) this inhibition occurred at 1:1 Zn:Fe wt/wt ratio. This differential response could be explained by the variation in the abundance of both cations as they compete for a limited number of shared transporters at the enterocyte. Conflicting results have been obtained when this interaction was studied in different food matrices. A negative interaction was not observed when Fe and Zn were provided in a composite hamburger meal, premature formula, human milk, or cow milk. A decrease on Fe absorption was observed in only 1 of 3 studies when Fe and Zn were supplied in wheat flour. The possibility of a negative interaction should be considered for supplementation or fortification programs with both microminerals.

  5. Nanoparticulate iron(III) oxo-hydroxide delivers safe iron that is well absorbed and utilised in humans

    Science.gov (United States)

    Pereira, Dora I.A.; Bruggraber, Sylvaine F.A.; Faria, Nuno; Poots, Lynsey K.; Tagmount, Mani A.; Aslam, Mohamad F.; Frazer, David M.; Vulpe, Chris D.; Anderson, Gregory J.; Powell, Jonathan J.

    2014-01-01

    Iron deficiency is the most common nutritional disorder worldwide with substantial impact on health and economy. Current treatments predominantly rely on soluble iron which adversely affects the gastrointestinal tract. We have developed organic acid-modified Fe(III) oxo-hydroxide nanomaterials, here termed nano Fe(III), as alternative safe iron delivery agents. Nano Fe(III) absorption in humans correlated with serum iron increase (P solubility. The most promising preparation (iron hydroxide adipate tartrate: IHAT) showed ~80% relative bioavailability to Fe(II) sulfate in humans and, in a rodent model, IHAT was equivalent to Fe(II) sulfate at repleting haemoglobin. Furthermore, IHAT did not accumulate in the intestinal mucosa and, unlike Fe(II) sulfate, promoted a beneficial microbiota. In cellular models, IHAT was 14-fold less toxic than Fe(II) sulfate/ascorbate. Nano Fe(III) manifests minimal acute intestinal toxicity in cellular and murine models and shows efficacy at treating iron deficiency anaemia. From the Clinical Editor This paper reports the development of novel nano-Fe(III) formulations, with the goal of achieving a magnitude less intestinal toxicity and excellent bioavailability in the treatment of iron deficiency anemia. Out of the tested preparations, iron hydroxide adipate tartrate met the above criteria, and may become an important tool in addressing this common condition. PMID:24983890

  6. Green tea or rosemary extract added to foods reduces nonheme- iron absorption

    DEFF Research Database (Denmark)

    Samman, S.; Sandstrøm, B.; Toft, M.B.

    2001-01-01

    the effect of phenolic-rich extracts obtained from green tea or rosemary on nonheme-iron absorption. Design: Young women aged 19-39 y consumed test meals on 4 separate occasions. The meals were identical except for the absence (meal A) or presence (meal B) of a phenolic-rich extract from green tea (study 1......-body retention of 59Fe and the ratio of Fe-55 to 59Fe activity in blood samples. Results: The presence of the phenolic-rich extracts resulted in decreased nonheme-iron absorption. Mean (+/-SD) iron absorption decreased from 12.1 +/- 4.5% to 8.9 +/- 5.2% (P tea extract and from 7...

  7. The effect of water on the stability of iron oxide and iron carbide nanoparticles in hydrogen and syngas followed by in situ X-ray absorption spectroscopy

    NARCIS (Netherlands)

    Thuene, P.C.; Moodley - Gengan, P.; Scheijen, F.J.E.; Fredriksson, H.O.A.; Lancee, R.J.; Kropf, J.; Miller, J.T.; Niemantsverdriet, J.W.

    2012-01-01

    The effect of water on iron-based nanoparticles under hydrogen and syngas was investigated by in situ X-ray absorption spectroscopy. The iron oxide (¿-Fe2O3) nanoparticles, dispersed as a monolayer on flat silica surfaces, were readily converted into metallic iron in dry hydrogen at 350 °C and into

  8. Iron interference in arsenic absorption by different plant species, analysed by neutron activation, k0-method

    International Nuclear Information System (INIS)

    Uemura, George; Matos, Ludmila Vieira da Silva; Silva, Maria Aparecida da; Menezes, Maria Angela de Barros Correia

    2009-01-01

    Natural arsenic contamination is a cause for concern in many countries of the world including Argentina, Bangladesh, Chile, China, India, Mexico, Thailand, United States of America and also in Brazil, specially in the Iron Quadrangle area, where mining activities have been contributing to aggravate natural contamination. Among other elements, iron is capable to interfere with the arsenic absorption by plants; iron ore has been proposed to remediate areas contaminated by the mentioned metalloid. In order to verify if iron can interfere with arsenic absorption by different taxa of plants, specimens of Brassicacea and Equisetaceae were kept in a 1/4 Murashige and Skoog basal salt solution (M and S), with 10 μgL -1 of arsenic acid. And varying concentrations of iron. The specimens were analysed by neutron activation analysis, k 0 -method, a routine technique in CDTN, and also very appropriate for arsenic studies. The preliminary results were quite surprising, showing that iron can interfere with arsenic absorption by plants, but in different ways, according to the species studied. (author)

  9. A study of phosphate absorption by magnesium iron hydroxycarbonate.

    Science.gov (United States)

    Du, Yi; Rees, Nicholas; O'Hare, Dermot

    2009-10-21

    A study of the mechanism of phosphate adsorption by magnesium iron hydroxycarbonate, [Mg(2.25)Fe(0.75)(OH)(6)](CO(3))(0.37).0.65H(2)O over a range of pH has been carried out. The efficiency of the phosphate removal from aqueous solution has been investigated between pH 3-9 and the resulting solid phases have been studied by elemental analysis, XRD, FT-IR, Raman, HRTEM, EDX and solid-state MAS (31)P NMR. The analytical and spectroscopic data suggest that phosphate removal from solution occurs not by anion intercalation of the relevant phosphorous oxyanion (H(2)PO(4)(-) or HPO(4)(2-)) into the LDH but by the precipitation of either an insoluble iron hydrogen phosphate hydrate and/or a magnesium phosphate hydrate.

  10. The Effects of Dietary Calcium and/or Iron Deficiency upon Murine Intestinal Calcium Binding Protein Activity and Calcium Absorption

    OpenAIRE

    McDonald, Catherine M.

    1980-01-01

    Iron deficiency has been shown to impair calcium absorption, leading to decreased bone mass. Vitamin D3-dependent calcium binding protein (CaBP) has been demonstrated to be necessary for the active transport of calcium in the intestine of numerous species. Iron deficiency might affect the activity of the calcium binding protein. Four experimental diets were formulated as follows: Diet 1, iron adequate, calcium adequate; Diet 2, iron deficient, calcium adequate; Diet 3, iron adequate, calci...

  11. In overweight and obese women, dietary iron absorption is reduced and the enhancement of iron absorption by ascorbic acid is one-half that in normal-weight women

    NARCIS (Netherlands)

    Cepeda-Lopez, A.C.; Melse, A.; Zimmermann, M.B.; Herter-Aeberli, I.

    2015-01-01

    Background: Iron deficiency is common in overweight and obese individuals. This deficiency may be due to adiposity-related inflammation that increases serum hepcidin and decreases dietary iron absorption. Because hepcidin reduces iron efflux from the basolateral enterocyte, it is uncertain whether

  12. Ferrous and hemoglobin-59Fe absorption from supplemented cow milk in infants with normal and depleted iron stores

    International Nuclear Information System (INIS)

    Heinrich, H.C.; Gabbe, E.E.; Whang, D.H.; Bender-Goetze, C.; Schaefer, K.H.; Hamburg Univ.

    1975-01-01

    Small amounts of milk do inhibit ferrous iron absorption from a 5 mg 59 Fe 2+ dose in 1- to 18-month-old infants. Only 50 ml of 2/3 cow milk reduced the absorption from 18 to 3.8% in infants with normal iron stores (inhibition index 0.21) and from 26 to 8.5% in [de

  13. Effect of excess supply of heavy metals on the absorption and translocation of iron (/sup 59/Fe) in barley

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, C P; Bisht, S S; Agarwala, S C [Lucknow Univ. (India). Dept. of Botany

    1978-03-01

    The effects of an excess supply of manganese, copper, zinc, cobalt, and nickel on the absorption and translocation of iron tagged with /sup 59/Fe were xamined in 15 days old barley seedlings raised in solution culture. Excess heavy metal treatments and /sup 59/Fe were administered in three different ways: (i) both excess heavy metals and iron supplied through roots- Series A; (ii) excess heavy metal supplied as foliar spray and iron through roots- Series B; and (iii) excess heavy metal supplied through roots and iron as foliar spray-Series C. Results obtained revealed that excess concentrations of manganese, zinc, cobalt, and a to a lesser extent copper interfered with the absorption of iron from the rooting medium, but excess nickel enhanced the absorption and translocation of iron. Thus, unlike other metals, a toxic supply of nickel does not induce iron deficiency.

  14. Prebiotics increase heme iron bioavailability and do not affect non-heme iron bioavailability in humans.

    Science.gov (United States)

    Weinborn, Valerie; Valenzuela, Carolina; Olivares, Manuel; Arredondo, Miguel; Weill, Ricardo; Pizarro, Fernando

    2017-05-24

    The aim of this study was to establish the effect of a prebiotic mix on heme and non-heme iron (Fe) bioavailability in humans. To this purpose, twenty-four healthy women were randomized into one of two study groups. One group ate one yogurt per day for 12 days with a prebiotic mix (prebiotic group) and the other group received the same yogurt but without the prebiotic mix (control group). Before and after the intake period, the subjects participated in Fe absorption studies. These studies used 55 Fe and 59 Fe radioactive isotopes as markers of heme Fe and non-heme Fe, respectively, and Fe absorption was measured by the incorporation of radioactive Fe into erythrocytes. The results showed that there were no significant differences in heme and non-heme Fe bioavailability in the control group. Heme Fe bioavailability of the prebiotic group increased significantly by 56% post-prebiotic intake. There were no significant differences in non-heme Fe bioavailability in this group. We concluded that daily consumption of a prebiotic mix increases heme Fe bioavailability and does not affect non-heme iron bioavailability.

  15. Liquid-Liquid Extraction and Determination of Trace Elements in Iron Minerals by Atomic Absorption Spectrometry

    International Nuclear Information System (INIS)

    Taseska, Milena; Stafilov, Trajche; Makreski, Petre; Jacimovic, Radojko; Jovanovski, Gligor

    2006-01-01

    Various trace elements (cadmium, chromium, cobalt, nickel, manganese) in some iron minerals were determined by flame (FAAS) and electrothermal atomic absorption spectrometry (ETAAS). The studied minerals were chalcopyrite (CuFeS 2 ), hematite (Fe 2 O 3 ) and pyrite (FeS 2 ). To avoid the interference of iron, a method for liquid-liquid extraction of iron and determination of investigated elements in the inorganic phase was proposed. Iron was extracted by diisopropyl ether in hydrochloride acid solution and the extraction method was optimized. Some parameters were obtained to be significantly important: Fe mass in the sample should not exceed 0.3 g, the optimal concentration of HCI should be 7.8 mol 1 -1 and ratio of the inorganic and organic phase should be 1: 1. The procedure was verified by the method of standard additions and by its applications to reference standard samples. The investigated minerals originate from various mines in the Republic of Macedonia. (Author)

  16. Study of the pattern of iron absorption and utilization in anaemias associated with malnutrition

    International Nuclear Information System (INIS)

    Ahmed, K.

    1976-06-01

    The objective of this investigation was to observe in poor populations, generally malnourished and anemic, the effect on hemoglobin level and percentage iron absorption of (1) an improved diet and (2) vitamin C supplementation alone. Percentage iron absorption was measured, after consumption of a meal into which 3-5 μCi 59 Fe as ferrous sulphate had been homogeneously mixed, by whole-body counting and also by measuring the concentration of the isotope in the blood at about two weeks. As subjects of the investigation were used adult males and females, from poor local population groups, who had no hookworm or other problems causing bleeding. A total of 236 subjects, subsequent to a preliminary screening and performance of appropriate laboratory tests, were placed on an improved diet containing about 300 g/d protein in the form of fish, meat, and pulses, plus leafy vegetables. It could not be assured, however, that all continued to take this diet during most of the 90-180 d test period during which they lived at home. Measurements were made of hemoglobin level and percentage absorption of iron from a test meal, before and after the test period of improved nutrition. In females the hemoglobin level (g/100 ml blood) rose from 10.2+-0.5 to 12.4+-0.4, and in males from 9.8+-0.4 to 12.3+-0.5, where errors quoted are standard errors of the mean. In females the percentage iron absorption rose from 18.8%+-1.8% to 24.5%+-2.5%, and in males from 14.4%+-1.6% to 19.2%+-2.2%. All the increases were judged to be statistically significant. Another group of 220 subjects, after preliminary screening, were told to take vitamin C supplements of 100 mg/d with their two principal meals over a period of 90-120 days. Hemoglobin levels, but not iron absorption from a test meal containing no supplement of vitamin C, was found to be statistically significantly improved at the end of the test period. This confirms the potential of vitamin C as a supplement for improving absorption of dietary

  17. Electrochemical permeation tests on the kinetics of the hydrogen absorption of palladium and iron

    International Nuclear Information System (INIS)

    Dafft, E.G.

    1977-01-01

    Electrochemical permeation tests were performed to investigate the kinetics of the hydrogen development and hydrogen absorption. The cathode side of the samples was galvanostatically cathodically polarized in different electrolyte solutions with and without additions. THe hydrogen atoms diffusing out of the opposite side for iron and α-palladium were oxidized with potentiostatic, sufficiently anodic polarization. The thus registered stationary current is proportional to the hydrogen activity on the cathode side. Test apparatus and conditions are described. The measurements on iron are discussed. (orig./HPOE) [de

  18. The determination of aluminum, copper, iron, and lead in glycol formulations by atomic absorption spectroscopy

    Science.gov (United States)

    1977-01-01

    Initial screening tests and the results obtained in developing procedures to determine Al, Cu, Fe, and Pb in glycol formulations are described. Atomic absorption completion was selected for Cu, Fe and Pb, and after comparison with emission spectroscopy, was selected for Al also. Before completion, carbon, iron, and lead are extracted with diethyl dithio carbamate (DDC) into methyl isobutyl ketone (MIBK). Aluminum was also extracted into MIBK using 8-hydroxyquinoline as a chelating agent. As little as 0.02 mg/l carbon and 0.06 mg/l lead or iron may be determined in glycol formulations. As little as 0.3 mg/l aluminum may be determined.

  19. The effect of haem biosynthesis inhibitors and inducers on intestinal iron absorption and liver haem biosynthetic enzyme activities

    International Nuclear Information System (INIS)

    Laftah, A.H.; Simpson, R.J.; Peters, T.J.; Raja, K.B.

    2008-01-01

    The relation between haem biosynthesis and intestinal iron absorption is not well understood, we therefore investigated the effect of compounds that alter haem metabolism on duodenal iron absorption. CD1 mice were treated with either an inhibitor (succinyl acetone (SA)) or stimulator (2-allyl-2-isopropylacetamide (AIA)) of haem biosynthesis. 5-Aminolaevulinic acid (ALA) dehydratase and urinary ALA and porphobilinogen (PBG) levels, were determined. Intestinal iron absorption was assayed with in vivo and in vitro techniques. Liver hepcidin (Hamp1) and duodenal iron transporter mRNA levels were measured using RT-PCR. AIA caused increased hepatic ALA synthase (1.6-fold) and ALA dehydratase (1.4-fold, both p < 0.005) activities and increased urinary ALA and PBG excretion (2.1- and 1.4-fold, p < 0.005, p < 0.05, respectively). In vivo intestinal iron absorption was reduced to 49% of control (p < 0.005). Mice treated with SA showed decreased urinary ALA and PBG levels (75 and 55% control, both p < 0.005) and reductions in both ALA synthase and ALA dehydratase activities (77 and 56% control, p < 0.05, p < 0.005, respectively) in the liver. Liver and duodenal haem and cytochrome oxidase levels were not significantly decreased. Iron absorption was enhanced (1.26-fold, p < 0.05) and hepatic Hamp1 mRNA was reduced (53% of control, p < 0.05). In vitro duodenal iron uptake after mice were injected with SA also demonstrated an increase in Fe(III) reduction and uptake (1.27- and 1.41-fold, p < 0.01 respectively). Simultaneous injections of SA and ALA blocked the enhancing effect on iron absorption seen with SA alone. We conclude that alterations in haem biosynthesis can influence iron absorption and in particular, the intermediate ALA seems to be an inhibitor of iron absorption

  20. Dephytinisation with Intrinsic Wheat Phytase and Iron Fortification Significantly Increase Iron Absorption from Fonio (Digitaria exilis) Meals in West African Women

    Science.gov (United States)

    Moretti, Diego; Schuth, Stephan; Egli, Ines; Zimmermann, Michael B.; Brouwer, Inge D.

    2013-01-01

    Low iron and high phytic acid content make fonio based meals a poor source of bioavailable iron. Phytic acid degradation in fonio porridge using whole grain cereals as phytase source and effect on iron bioavailability when added to iron fortified fonio meals were investigated. Grains, nuts and seeds collected in Mali markets were screened for phytic acid and phytase activity. We performed an iron absorption study in Beninese women (n = 16), using non-dephytinised fonio porridge (FFP) and dephytinised fonio porridge (FWFP; 75% fonio-25% wheat), each fortified with 57Fe or 58Fe labeled FeSO4. Iron absorption was quantified by measuring the erythrocyte incorporation of stable iron isotopes. Phytic acid varied from 0.39 (bambara nut) to 4.26 g/100 g DM (pumpkin seed), with oilseeds values higher than grains and nuts. Phytase activity ranged from 0.17±1.61 (fonio) to 2.9±1.3 phytase unit (PU) per g (whole wheat). Phytic acid was almost completely degraded in FWFP after 60 min of incubation (pH≈5.0, 50°C). Phytate∶iron molar ratios decreased from 23.7∶1 in FFP to 2.7∶1 in FWFP. Iron fortification further reduced phytate∶iron molar ratio to 1.9∶1 in FFP and 0.3∶1 in FWFP, respectively. Geometric mean (95% CI) iron absorption significantly increased from 2.6% (0.8–7.8) in FFP to 8.3% (3.8–17.9) in FWFP (Pphytase increased fractional iron absorption 3.2 times, suggesting it could be a possible strategy to decrease PA in cereal-based porridges. PMID:24124445

  1. Absorption of orally administered 65Zn by normal human subjects

    International Nuclear Information System (INIS)

    Aamodt, R.L.; Rumble, W.F.; Johnston, G.S.; Markley, E.J.; Henkin, R.I.

    1981-01-01

    Despite studies by several investigators of human gastrointestinal 65Zn absorption, implications of these data for evaluation of functional zinc status are unclear because limited numbers of normal subjects have been studied. To evaluated zinc absorption in normal humans, 75 subjects (31 women, 44 men, ages 18 to 84 yr) were given 10 micro Ci carrier-free 65Zn orally after an overnight fast. Absorption calculated from total body retention measured 7, 14, and 21 days after administration of tracer was 65 +/- 11% (mean +/- 1 SD), range from 40 to 86%. Comparison of these results with those for patients with a variety of diseases indicate that patients exhibit a wider range of absorption and, in four of six studies patients exhibit decreased mean zinc absorption. These results of gastrointestinal zinc absorption in a large number of normal humans offer a basis for a clearer comparison with data from patients who exhibit abnormalities of zinc absorption

  2. Consumption of galacto-oligosaccharides increases iron absorption from a micronutrient powder containing ferrous fumarate and sodium iron EDTA: a stable-isotope study in Kenyan infants.

    Science.gov (United States)

    Paganini, Daniela; Uyoga, Mary A; Cercamondi, Colin I; Moretti, Diego; Mwasi, Edith; Schwab, Clarissa; Bechtler, Salome; Mutuku, Francis M; Galetti, Valeria; Lacroix, Christophe; Karanja, Simon; Zimmermann, Michael B

    2017-10-01

    Background: Whether consumption of prebiotics increases iron absorption in infants is unclear. Objective: We set out to determine whether prebiotic consumption affects iron absorption from a micronutrient powder (MNP) containing a mixture of ferrous fumarate and sodium iron EDTA (FeFum+NaFeEDTA) in Kenyan infants. Design: Infants ( n = 50; aged 6-14 mo) consumed maize porridge that was fortified with an MNP containing FeFum+NaFeEDTA and 7.5 g galacto-oligosaccharides (GOSs) (Fe+GOS group, n = 22) or the same MNP without GOSs (Fe group, n = 28) each day for 3 wk. Then, on 2 consecutive days, we fed all infants isotopically labeled maize porridge and MNP test meals containing 5 mg Fe as 57 FeFum+Na 58 FeEDTA or ferrous sulfate ( 54 FeSO 4 ). Iron absorption was measured as the erythrocyte incorporation of stable isotopes. Iron markers, fecal pH, and bacterial groups were assessed at baseline and 3 wk. Comparisons within and between groups were done with the use of mixed-effects models. Results: There was a significant group-by-compound interaction on iron absorption ( P = 0.011). The median percentages of fractional iron absorption from FeFum+NaFeEDTA and from FeSO 4 in the Fe group were 11.6% (IQR: 6.9-19.9%) and 20.3% (IQR: 14.2-25.7%), respectively, ( P iron absorption was greater from the FeFum+NaFeEDTA ( P = 0.047) in the Fe+GOS group but not from the FeSO 4 ( P = 0.653). The relative iron bioavailability from FeFum+NaFeEDTA compared with FeSO 4 was higher in the Fe+GOS group than in the Fe group (88% compared with 63%; P = 0.006). There was a significant time-by-group interaction on Bifidobacterium spp. ( P = 0.008) and Lactobacillus / Pediococcus / Leuconostoc spp. ( P = 0.018); Lactobacillus / Pediococcus / Leuconostoc spp. decreased in the Fe group ( P = 0.013), and there was a nonsignificant trend toward higher Bifidobacterium spp. in the Fe+GOS group ( P = 0.099). At 3 wk, iron absorption was negatively correlated with fecal pH ( P iron absorption by 62

  3. Tertiary structural changes and iron release from human serum transferrin.

    Science.gov (United States)

    Mecklenburg, S L; Donohoe, R J; Olah, G A

    1997-08-01

    Iron release from human serum transferrin was investigated by comparison of the extent of bound iron, measured by charge transfer absorption band intensity (465 nm), with changes observed by small-angle solution X-ray scattering (SAXS) for a series of equilibrated samples between pH 5.69 and 7.77. The phosphate buffers used in this study promote iron release at relatively high pH values, with an empirical pK of 6.9 for the convolved release from the two sites. The spectral data reveal that the N-lobe release is nearly complete by pH 7.0, while the C-lobe remains primarily metal-laden. Conversely, the radius of gyration, Rg, determined from the SAXS data remains constant between pH 7.77 and 7.05, and the evolution of Rg between its value observed for the diferric protein at pH 7.77 (31.2+/-0.2 A) and that of the apo protein at pH 5.69 (33.9+/-0.4 A) exhibits an empirical pK of 6.6. While Rg is effectively constant in the pH range associated with iron release from the N-lobe, the radius of gyration of cross-section, Rc, increases from 16.9+/-0.2 A to 17.6+/-0.2 A. Model simulations suggest that two different rotations of the NII domain relative to the NI domain about a hinge deep in the iron-binding cleft of the N-lobe, one parallel with and one perpendicular to the plane of the iron-binding site, can be significantly advanced relative to their holo protein positions while yielding constant Rg and increased Rc values consistent with the scattering data. Rotation of the CII domain parallel with the C-lobe iron-binding site plane can partially account for the increased Rg values measured at low pH; however, no reasonable combined repositioning of the NII and CII domains yields the experimentally observed increase in Rg.

  4. The role of iron and black carbon in aerosol light absorption

    Directory of Open Access Journals (Sweden)

    Y. Derimian

    2008-07-01

    Full Text Available Iron is a major component of atmospheric aerosols, influencing the light absorption ability of mineral dust, and an important micronutrient that affects oceanic biogeochemistry. The regional distribution of the iron concentration in dust is important for climate studies; however, this is difficult to obtain since it requires in-situ aerosol sampling or simulation of complex natural processes. Simultaneous studies of aerosol chemical composition and radiometric measurements of aerosol optical properties, which were performed in the Negev desert of Israel continuously for about eight years, suggest a potential for deriving a relationship between chemical composition and light absorption properties, in particular the spectral single-scattering albedo.

    The two main data sets of the present study were obtained by a sun/sky radiometer and a stacked filter unit sampler that collects particles in coarse and fine size fractions. Analysis of chemical and optical data showed the presence of mixed dust and pollution aerosol in the study area, although their sources appear to be different. Spectral SSA showed an evident response to increased concentrations of iron, black carbon equivalent matter, and their mixing state. A relationship that relates the spectral SSA, the percentage of iron in total particulate mass, and the pollution components was derived. Results calculated, using this relationship, were compared with measurements from dust episodes in several locations around the globe. The comparison showed reasonable agreement between the calculated and the observed iron concentrations, and supported the validity of the suggested approach for the estimation of iron concentrations in mineral dust.

  5. Influence of food tannins on certain aspects of iron metabolism : Part 1 -- Absorption and excretion in normal and anemic rats

    Energy Technology Data Exchange (ETDEWEB)

    Roy, S N [Albert Einstein Coll. of Medicine, Bronx, NY (USA); Mukher ee, S [Calcutta Univ. (India). Dept. of Applied Chemistry

    1979-04-01

    Studies on absorption and excretion of iron by isotopic and non-isotopic methods in normal and hemolytic anemic rats indicate that dietary food tannins at a dose of 0.5 mg/kg body wt/day tend to increase iron excretion in normal rats but more iron is absorbed or retained in tannin-fed anemic rats and absorption of iron is comparable to that in normal control. Both in vivo and in vitro tannin at a high dose (2.0 mg/kg body wt/day) inhibits the iron absorption in experimental animals. The interference of food tannins (0.5 kg/mg body wt/day) with absorption of iron (/sup 59/Fe) varies with plant species from which tannin has been prepared. Normal iron balance in tannin-fed (0.5 mg/kg body wt/day) anemic rats may result from increased assimilation of tannin-bound iron in intestinal mucosa, and absorbed tannin appears to remove unabsorbed iron.

  6. Cimetidine absorption in humans during sucralfate coadministration.

    OpenAIRE

    D'Angio, R; Mayersohn, M; Conrad, K A; Bliss, M

    1986-01-01

    Cimetidine absorption after a single 300 mg oral dose was evaluated in six normal subjects in the absence or presence of sucralfate. Sucralfate was ingested four times a day for 2 days prior to and for two additional doses on the day of cimetidine ingestion. Sucralfate coadministration had no statistically significant influence on the rate or extent of cimetidine absorption.

  7. Multi-Copper Oxidases and Human Iron Metabolism

    Science.gov (United States)

    Vashchenko, Ganna; MacGillivray, Ross T. A.

    2013-01-01

    Multi-copper oxidases (MCOs) are a small group of enzymes that oxidize their substrate with the concomitant reduction of dioxygen to two water molecules. Generally, multi-copper oxidases are promiscuous with regards to their reducing substrates and are capable of performing various functions in different species. To date, three multi-copper oxidases have been detected in humans—ceruloplasmin, hephaestin and zyklopen. Each of these enzymes has a high specificity towards iron with the resulting ferroxidase activity being associated with ferroportin, the only known iron exporter protein in humans. Ferroportin exports iron as Fe2+, but transferrin, the major iron transporter protein of blood, can bind only Fe3+ effectively. Iron oxidation in enterocytes is mediated mainly by hephaestin thus allowing dietary iron to enter the bloodstream. Zyklopen is involved in iron efflux from placental trophoblasts during iron transfer from mother to fetus. Release of iron from the liver relies on ferroportin and the ferroxidase activity of ceruloplasmin which is found in blood in a soluble form. Ceruloplasmin, hephaestin and zyklopen show distinctive expression patterns and have unique mechanisms for regulating their expression. These features of human multi-copper ferroxidases can serve as a basis for the precise control of iron efflux in different tissues. In this manuscript, we review the biochemical and biological properties of the three human MCOs and discuss their potential roles in human iron homeostasis. PMID:23807651

  8. The Battle for Iron between Humans and Microbes.

    Science.gov (United States)

    Carver, Peggy L

    2018-01-01

    Iron is an essential micronutrient for bacteria, fungi, and humans; as such, each has evolved specialized iron uptake systems to acquire iron from the extracellular environment. To describe complex 'tug of war' for iron that has evolved between human hosts and pathogenic microorganisms in the battle for this vital nutrient. A review of current literature was performed, to assess current approaches and controversies in iron therapy and chelation in humans. In humans, sequestration (hiding) of iron from invading pathogens is often successful; however, many pathogens have evolved mechanisms to circumvent this approach. Clinically, controversy continues whether iron overload or administration of iron results in an increased risk of infection. The administration of iron chelating agents and siderophore- conjugate drugs to infected hosts seems a biologically plausible approach as adjunctive therapy in the treatment of infections caused by pathogens dependent on host iron supply (e.g. tuberculosis, malaria, and many bacterial and fungal pathogens); however, thus far, studies in humans have proved unsuccessful. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. Redox behaviors of iron by absorption spectroscopy and redox potential measurement

    International Nuclear Information System (INIS)

    Oh, Jae Yong

    2010-02-01

    This work is performed to study the redox (reduction/oxidation) behaviors of iron in aqueous system by a combination of absorption spectroscopy and redox potential measurements. There are many doubts on redox potential measurements generally showing low accuracies and high uncertainties. In the present study, redox potentials are measured by utilizing various redox electrodes such as Pt, Au, Ag, and glassy carbon (GC) electrodes. Measured redox potentials are compared with calculated redox potentials based on the chemical oxidation speciation of iron and thermodynamic data by absorption spectroscopy, which provides one of the sensitive and selective spectroscopic methods for the chemical speciation of Fe(II/III). From the comparison analyses, redox potential values measured by the Ag redox electrode are fairly consistent with those calculated by the chemical aqueous speciation of iron in the whole system. In summary, the uncertainties of measured redox potentials are closely related with the total Fe concentration and affected by the formation of mixed potentials due to Fe(III) precipitates in the pH range of 6 ∼ 9 beyond the solubility of Fe(III), whilst being independent of the initially prepared concentration ratios between Fe(II) and Fe(III)

  10. Determination of iron in natural and mineral waters by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    ROLANDAS KAZLAUSKAS

    2004-05-01

    Full Text Available Simple methods for the determination of Fe in natural and mineral waters by flame atomic absorption spectrometry (AAS are suggested. The results of the investigation of selectivity of the proposed AAS method proved that this procedure is not affected by high concentrations of other metals. The calibration graph for iron was linear at levels near the detection limit up to at least 0.10 mg ml-1. For the determination of microamounts of iron in mineral waters, an extraction AAS technique was developed. Iron was retained as Fe-8-oxyquinoline complex and extracted into chloroform. The optimal conditions for the extraction of the iron complex were determined. The AAS method was applied to the determination of Fe in mineral waters and natural waters from different areas of Lithuania. The accuracy of the developed method was sufficient and evaluated in comparison with a photometric method. The obtained results demonstrated that the procedure could be successfully applied for the analysis of water samples with satisfactory accuracy.

  11. Absorption of l-methionine from the human small intestine

    Science.gov (United States)

    Schedl, Harold P.; Pierce, Charles E.; Rider, Alan; Clifton, James A.

    1968-01-01

    Absorption of L-methionine was measured in all parts of the human small intestine using transintestinal intubation and perfusion. In four normal subjects, adsorption was higher in the proximal than in the distal intestine. In two patients with nontropical sprue in relapse, there was a proximal zone of low absorption with higher absorption distally. In all parts of the small intestine, absorption showed rate-limiting kinetics as methionine concentration was increased. In normal subjects, the proximal Km (Michaelis constant) was more than 3 times higher than the distal, which suggests a difference in transport mechanisms between the two segments. PMID:12066784

  12. A theoretical and experimental study of calcium, iron, zinc, cadmium, and sodium ions absorption by aspartame.

    Science.gov (United States)

    Mahnam, Karim; Raisi, Fatame

    2017-03-01

    Aspartame (L-Aspartyl-L-phenylalanine methyl ester) is a sweet dipeptide used in some foods and beverages. Experimental studies show that aspartame causes osteoporosis and some illnesses, which are similar to those of copper and calcium deficiency. This raises the issue that aspartame in food may interact with cations and excrete them from the body. This study aimed to study aspartame interaction with calcium, zinc, iron, sodium, and cadmium ions via molecular dynamics simulation (MD) and spectroscopy. Following a 480-ns molecular dynamics simulation, it became clear that the aspartame is able to sequester Fe 2+ , Ca 2+ , Cd 2+ , and Zn 2+ ions for a long time. Complexation led to increasing UV-Vis absorption spectra and emission spectra of the complexes. This study suggests a potential risk of cationic absorption of aspartame. This study suggests that purification of cadmium-polluted water by aspartame needs a more general risk assessment.

  13. Siderophore-mediated iron trafficking in humans is regulated by iron

    Science.gov (United States)

    Liu, Zhuoming; Lanford, Robert; Mueller, Sebastian; Gerhard, Glenn S.; Luscieti, Sara; Sanchez, Mayka; Devireddy, L.

    2013-01-01

    Siderophores are best known as small iron binding molecules that facilitate microbial iron transport. In our previous study we identified a siderophore-like molecule in mammalian cells and found that its biogenesis is evolutionarily conserved. A member of the short chain dehydrogenase family of reductases, 3-OH butyrate dehydrogenase (BDH2) catalyzes a rate-limiting step in the biogenesis of the mammalian siderophore. We have shown that depletion of the mammalian siderophore by inhibiting expression of bdh2 results in abnormal accumulation of cellular iron and mitochondrial iron deficiency. These observations suggest that the mammalian siderophore is a critical regulator of cellular iron homeostasis and facilitates mitochondrial iron import. By utilizing bioinformatics, we identified an iron-responsive element (IRE; a stem-loop structure that regulates genes expression post-transcriptionally upon binding to iron regulatory proteins or IRPs) in the 3′-untranslated region (3′-UTR) of the human BDH2 (hBDH2) gene. In cultured cells as well as in patient samples we now demonstrate that the IRE confers iron-dependent regulation on hBDH2 and binds IRPs in RNA electrophoretic mobility shift assays. In addition, we show that the hBDH2 IRE associates with IRPs in cells and that abrogation of IRPs by RNAi eliminates the iron-dependent regulation of hBDH2 mRNA. The key physiologic implication is that iron-mediated post-transcriptional regulation of hBDH2 controls mitochondrial iron homeostasis in human cells. These observations provide a new and an unanticipated mechanism by which iron regulates its intracellular trafficking. PMID:22527885

  14. A 1-h time interval between a meal containing iron and consumption of tea attenuates the inhibitory effects on iron absorption: a controlled trial in a cohort of healthy UK women using a stable iron isotope.

    Science.gov (United States)

    Ahmad Fuzi, Salma F; Koller, Dagmar; Bruggraber, Sylvaine; Pereira, Dora Ia; Dainty, Jack R; Mushtaq, Sohail

    2017-12-01

    Background: Tea has been shown to be a potent inhibitor of nonheme iron absorption, but it remains unclear whether the timing of tea consumption relative to a meal influences iron bioavailability. Objective: The aim of the study was to investigate the effect of a 1-h time interval of tea consumption on nonheme iron absorption in an iron-containing meal in a cohort of iron-replete, nonanemic female subjects with the use of a stable isotope ( 57 Fe). Design: Twelve women (mean ± SD age: 24.8 ± 6.9 y) were administered a standardized porridge meal extrinsically labeled with 4 mg 57 Fe as FeSO 4 on 3 separate occasions, with a 14-d time interval between each test meal (TM). The TM was administered with water (TM-1), with tea administered simultaneously (TM-2), and with tea administered 1 h postmeal (TM-3). Fasted venous blood samples were collected for iron isotopic analysis and measurement of iron status biomarkers. Fractional iron absorption was estimated by the erythrocyte iron incorporation method. Results: Iron absorption was 5.7% ± 8.5% (TM-1), 3.6% ± 4.2% (TM-2), and 5.7% ± 5.4% (TM-3). Mean fractional iron absorption was found to be significantly higher (2.2%) when tea was administered 1 h postmeal (TM-3) than when tea was administered simultaneously with the meal (TM-2) ( P = 0.046). An ∼50% reduction in the inhibitory effect of tea (relative to water) was observed, from 37.2% (TM-2) to 18.1% (TM-3). Conclusions: This study shows that tea consumed simultaneously with an iron-containing porridge meal leads to decreased nonheme iron absorption and that a 1-h time interval between a meal and tea consumption attenuates the inhibitory effect, resulting in increased nonheme iron absorption. These findings are not only important in relation to the management of iron deficiency but should also inform dietary advice, especially that given to those at risk of deficiency. This trial was registered at clinicaltrials.gov as NCT02365103. © 2017 American Society for

  15. The expression of the soluble HFE corresponding transcript is up-regulated by intracellular iron and inhibits iron absorption in a duodenal cell model

    OpenAIRE

    Silva, Bruno; Ferreira, Joana; Santos, Vera; Baldaia, Cilénia; Serejo, Fátima; Faustino, Paula

    2014-01-01

    Background and aims: Dietary iron absorption regulation is a key-step for the maintenance of body iron homeostasis. Besides the HFE full-length protein, the HFE gene codes for alternative splicing variants responsible for the synthesis of a soluble form of HFE protein (sHFE). Here we aimed to determine whether sHFE transcript levels respond to different iron conditions in duodenal, macrophage and hepatic cell models, as well, in vivo, in the liver. Furthermore, we determined the functional ef...

  16. Increasing the cooking temperature of meat does not affect nonheme iron absorption from a phytate-rich meal in women

    DEFF Research Database (Denmark)

    Baech, S.B.; Hansen, M.; Bukhave, Klaus

    2003-01-01

    The effect of increasing cooking temperatures of meat on nonheme iron absorption from a composite meal was investigated. Cysteine-containing peptides may have a role in the iron absorption enhancing effect of muscle proteins. Heat treatment can change the content of sulfhydryl groups produced from...... cysteine and thereby affect iron absorption. Twenty-one women (25 +/- 3 y) were served a basic meal without meat and two other meals consisting of the basic meal plus 75 g of pork meat cooked at 70, 95 or 120degreesC. The meals were extrinsically labeled with Fe-55 or Fe-59. Iron absorption was determined...... from measurements of wholebody Fe-59 retention and the activity of Fe-55 and Fe-59 in blood samples. Nonheme iron absorptions were 0.9 (0.5-4.0)% (P = 0.06), 0.7 (0.4-3.9)% (P = 0.1) and 2.0 (1.3-3.1)% (P cooked at 70, 95 or 120degreesC, respectively, was added to the basic...

  17. Transport Measurements and Synchrotron-Based X-Ray Absorption Spectroscopy of Iron Silicon Germanide Grown by Molecular Beam Epitaxy

    Science.gov (United States)

    Elmarhoumi, Nader; Cottier, Ryan; Merchan, Greg; Roy, Amitava; Lohn, Chris; Geisler, Heike; Ventrice, Carl, Jr.; Golding, Terry

    2009-03-01

    Some of the iron-based metal silicide and germanide phases have been predicted to be direct band gap semiconductors. Therefore, they show promise for use as optoelectronic materials. We have used synchrotron-based x-ray absorption spectroscopy to study the structure of iron silicon germanide films grown by molecular beam epitaxy. A series of Fe(Si1-xGex)2 thin films (2000 -- 8000å) with a nominal Ge concentration of up to x = 0.04 have been grown. X-ray absorption near edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) measurements have been performed on the films. The nearest neighbor co-ordination corresponding to the β-FeSi2 phase of iron silicide provides the best fit with the EXAFS data. Temperature dependent (20 coefficient was calculated. Results suggest semiconducting behavior of the films which is consistent with the EXAFS results.

  18. Determination of oxidation state of iron in normal and pathologically altered human aortic valves

    Energy Technology Data Exchange (ETDEWEB)

    Czapla-Masztafiak, J. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Kraków (Poland); Lis, G.J.; Gajda, M.; Jasek, E. [Department of Histology, Jagiellonian University Medical College, Kopernika 7, 31-034 Kraków (Poland); Czubek, U. [Department of Coronary Disease, Jagiellonian University Medical College, John Paul II Hospital, Prądnicka 80, 31-202 Kraków (Poland); Bolechała, F. [Department of Forensic Medicine, Jagiellonian University Medical College, Grzegórzecka 16, 31-531 Kraków (Poland); Borca, C. [Swiss Light Source, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Kwiatek, W.M. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Kraków (Poland)

    2015-12-01

    In order to investigate changes in chemical state of iron in normal and pathologically altered human aortic valves X-ray absorption spectroscopy was applied. Since Fe is suspected to play detrimental role in aortic valve stenosis pathogenesis the oxidation state of this element has been determined. The experimental material consisted of 10 μm sections of valves excised during routine surgery and from autopsies. The experiment was performed at the MicroXAS beamline of the SLS synchrotron facility in Villigen (Switzerland). The Fe K-edge XANES spectra obtained from tissue samples were carefully analyzed and compared with the spectra of reference compounds containing iron in various chemical structures. The analysis of absorption edge position and shape of the spectra revealed that both chemical forms of iron are presented in valve tissue but Fe{sup 3+} is the predominant form. Small shift of the absorption edge toward higher energy in the spectra from stenotic valve samples indicates higher content of the Fe{sup 3+} form in pathological tissue. Such a phenomenon suggests the role of Fenton reaction and reactive oxygen species in the etiology of aortic valve stenosis. The comparison of pre-edge regions of XANES spectra for control and stenotic valve tissue confirmed no differences in local symmetry or spin state of iron in analyzed samples.

  19. Infrared absorption of human breast tissues in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Liu Chenglin [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China); Physics Department of Yancheng Teachers' College, Yancheng 224002 (China); Zhang Yuan [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China); Yan Xiaohui [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China); Zhang Xinyi [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China) and Shanghai Research Center of Acupuncture and Meridian, Pudong, Shanghai 201203 (China)]. E-mail: xy-zhang@fudan.edu.cn; Li Chengxiang [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Yang Wentao [Cancer Hospital, Medical Center, Fudan University, Shanghai 200032 (China); Shi Daren [Cancer Hospital, Medical Center, Fudan University, Shanghai 200032 (China)

    2006-07-15

    The spectral characteristics of human breast tissues in normal status and during different cancerous stages have been investigated by synchrotron radiation based Fourier transform infrared (SR-FTIR) absorption spectroscopy. Thanks to the excellent synchrotron radiation infrared (IR) source, higher resolving power is achieved in SR-FTIR absorption spectra than in conventional IR absorption measurements. Obvious variations in IR absorption spectrum of breast tissues were found as they change from healthy to diseased, or say in progression to cancer. On the other hand, some specific absorption peaks were found in breast cancer tissues by SR-FTIR spectroscopic methods. These spectral characteristics of breast tissue may help us in early diagnosis of breast cancer.

  20. Effect of the carbonyl iron particles on acoustic absorption properties of magnetic polyurethane foam

    Science.gov (United States)

    Geng, Jialu; Wang, Caiping; Zhu, Honglang; Wang, Xiaojie

    2018-03-01

    Elastomeric matrix embedded with magnetic micro-sized particles has magnetically controllable properties, which has been investigated extensively in the last decades. In this study we develop a new magnetically controllable elastomeric material for acoustic applications at lower frequencies. The soft polyurethane foam is used as matrix material due to its extraordinary elastic and acoustic absorption properties. One-step method is used to synthesize polyurethane foam, in which all components including polyether polyols 330N, MDI, deionized water, silicone oil, carbonyl iron particle (CIP) and catalyst are put into one container for curing. Changing any component can induce the change of polyurethane foam's properties, such as physical and acoustic properties. The effect of the content of MDI on acoustic absorption is studied. The CIPs are aligned under extra magnetic field during the foaming process. And the property of polyurethane foam with aligned CIPs is also investigated. Scanning electron microscope (SEM) is used to observe the structure of pore and particle-chain. The two-microphone impedance tube and the transfer function method are used to test acoustic absorption property of the magnetic foams.

  1. Vehicle effects on human stratum corneum absorption and skin penetration.

    Science.gov (United States)

    Zhang, Alissa; Jung, Eui-Chang; Zhu, Hanjiang; Zou, Ying; Hui, Xiaoying; Maibach, Howard

    2017-05-01

    This study evaluated the effects of three vehicles-ethanol (EtOH), isopropyl alcohol (IPA), and isopropyl myristate (IPM)-on stratum corneum (SC) absorption and diffusion of the [ 14 C]-model compounds benzoic acid and butenafine hydrochloride to better understand the transport pathways of chemicals passing through and resident in SC. Following application of topical formulations to human dermatomed skin for 30 min, penetration flux was observed for 24 h post dosing, using an in vitro flow-through skin diffusion system. Skin absorption and penetration was compared to the chemical-SC (intact, delipidized, or SC lipid film) binding levels. A significant vehicle effect was observed for chemical skin penetration and SC absorption. IPA resulted in the greatest levels of intact SC/SC lipid absorption, skin penetration, and total skin absorption/penetration of benzoic acid, followed by IPM and EtOH, respectively. For intact SC absorption and total skin absorption/penetration of butenafine, the vehicle that demonstrated the highest level of sorption/penetration was EtOH, followed by IPA and IPM, respectively. The percent doses of butenafine that were absorbed in SC lipid film and penetrated through skin in 24 h were greatest for IPA, followed by EtOH and IPM, respectively. The vehicle effect was consistent between intact SC absorption and total chemical skin absorption and penetration, as well as SC lipid absorption and chemical penetration through skin, suggesting intercellular transport as a main pathway of skin penetration for model chemicals. These results suggest the potential to predict vehicle effects on skin permeability with simple SC absorption assays. As decontamination was applied 30 min after chemical exposure, significant vehicle effects on chemical SC partitioning and percutaneous penetration also suggest that skin decontamination efficiency is vehicle dependent, and an effective decontamination method should act on chemical solutes in the lipid domain.

  2. Natural selection on HFE in Asian populations contributes to enhanced non-heme iron absorption.

    Science.gov (United States)

    Ye, Kaixiong; Cao, Chang; Lin, Xu; O'Brien, Kimberly O; Gu, Zhenglong

    2015-06-10

    HFE, a major regulator of iron (Fe) homeostasis, has been suggested to be under positive selection in both European and Asian populations. While the genetic variant under selection in Europeans (a non-synonymous mutation, C282Y) has been relatively well-studied, the adaptive variant in Asians and its functional consequences are still unknown. Identifying the adaptive HFE variants in Asians will not only elucidate the evolutionary history and the genetic basis of population difference in Fe status, but also assist the future practice of genome-informed dietary recommendation. Using data from the International HapMap Project, we confirmed the signatures of positive selection on HFE in Asian populations and identified a candidate adaptive haplotype that is common in Asians (52.35-54.71%) but rare in Europeans (5.98%) and Africans (4.35%). The T allele at tag SNP rs9366637 (C/T) captured 95.8% of this Asian-common haplotype. A significantly reduced HFE expression was observed in individuals carrying T/T at rs9366637 compared to C/C and C/T, indicating a possible role of gene regulation in adaptation. We recruited 57 women of Asian descent and measured Fe absorption using stable isotopes in those homozygous at rs9366637. We observed a 22% higher absorption in women homozygous for the Asian-common haplotype (T/T) compared to the control genotype (C/C). Additionally, compared with a group of age-matched Caucasian women, Asian women exhibited significantly elevated Fe absorption. Our results indicate parallel adaptation of HFE gene in Europeans and Asians with different genetic variants. Moreover, natural selection on HFE may have contributed to elevated Fe absorption in Asians. This study regarding population differences in Fe homeostasis has significant medical impact as high Fe level has been linked to an increased disease risk of metabolic syndromes.

  3. Isotope aided studies on the bioavailability of iron and zinc from human diets

    International Nuclear Information System (INIS)

    Raghuramulu, N.

    1992-01-01

    Iron deficiency anaemia is a major public health problem in many developing countries including India. Recent multicentric studies indicated that in rural population of India, 60% of preschool children and 40-60 % of women of child bearing age may suffer from anaemia. Studies by Sood et al indicated that iron stores are generally lower in the population as compared to populations in other countries. It is therefore possible that prelatent iron deficiency may be even higher who look otherwise healthy and adequately nourished. Iron absorption from habitual diets of Indians has been determined in the past by the chemical balance methods. Iron absorption determined by this method may be a gross over estimate. A more reliable estimate of iron absorption from composite meals can be obtained by the radio isotopic methods in which foods are extrinsically or intrinsically tagged with radio iron ( 55 Fe or 59 Fe). Using these methods iron absorption from a few habitual diets was studied. 15 refs

  4. Atomic absorption determination of iron and copper impurities in rare earth compounds

    International Nuclear Information System (INIS)

    Zelyukova, Yu.V.; Kravchenko, J.B.; Kucher, A.A.

    1978-01-01

    An extraction atomic absorption method for the determination of copper and iron impurities in rare earth compounds has been developed. The extraction separation of determined elements as hydroxy quinolinates with isobuthyl alcohol was used. It increased the sensitivity of these element determination and excluded the effect of the analysed sample. Cu, Te, Zn, Bi, Sn, In, Ga, Tl and the some other elements can be determined at pH 2.0-3.0 but rare earths are remained in an aqueous phase. The condition of the flame combustion does not change during the introduction of isobutyl extract but the sensitivity of the determination of the elements increased 2-3 times. The limit of Fe determination is 0.01 mg/ml and the limit of Cu determination is 0.014 mg/ml

  5. Large specific absorption rates in the magnetic hyperthermia properties of metallic iron nanocubes

    Energy Technology Data Exchange (ETDEWEB)

    Mehdaoui, B.; Meffre, A.; Lacroix, L.-M. [Universite de Toulouse, INSA, UPS, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), 135 avenue de Rangueil, F-31077 Toulouse (France); CNRS, UMR 5215, LPCNO, F-31077 Toulouse (France); Carrey, J., E-mail: julian.carrey@insa-toulouse.f [Universite de Toulouse, INSA, UPS, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), 135 avenue de Rangueil, F-31077 Toulouse (France); CNRS, UMR 5215, LPCNO, F-31077 Toulouse (France); Lachaize, S. [Universite de Toulouse, INSA, UPS, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), 135 avenue de Rangueil, F-31077 Toulouse (France); CNRS, UMR 5215, LPCNO, F-31077 Toulouse (France); Gougeon, M. [Institut CARNOT-CIRIMAT-UMR 5085, Batiment 2R1, 118 route de Narbonne, F-31062 Toulouse (France); Respaud, M. [Universite de Toulouse, INSA, UPS, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), 135 avenue de Rangueil, F-31077 Toulouse (France); CNRS, UMR 5215, LPCNO, F-31077 Toulouse (France); Chaudret, B. [Laboratoire de Chimie de Coordination-CNRS, 205 rte de Narbonne, 31077 Toulouse cedex 4 (France)

    2010-10-15

    We report on the magnetic hyperthermia properties of chemically synthesized ferromagnetic 11 and 16 nm Fe(0) nanoparticles of cubic shape displaying the saturation magnetization of bulk iron. The specific absorption rate measured on 16 nm nanocubes is 1690{+-}160 W/g at 300 kHz and 66 mT. This corresponds to specific losses-per-cycle of 5.6 mJ/g, largely exceeding the ones reported in other systems. A way to quantify the degree of optimization of any system with respect to hyperthermia applications is proposed. Applied here, this method shows that our nanoparticles are not fully optimized, probably due to the strong influence of magnetic interactions on their magnetic response. Once protected from oxidation and further optimized, such nano-objects could constitute efficient magnetic cores for biomedical applications requiring very large heating power.

  6. Facile preparation and enhanced microwave absorption properties of flake carbonyl iron/Fe3O4 composite

    International Nuclear Information System (INIS)

    Min, Dandan; Zhou, Wancheng; Luo, Fa; Zhu, Dongmei

    2017-01-01

    Highlights: • Flake carbonyl iron/Fe 3 O 4 composites were prepared by surface oxidation technique. • Lower permittivity and modest permeability was obtained by the FCI/Fe 3 O 4 composites. • Enhanced absorption efficiency and broader absorption band were obtained. - Abstract: Flake carbonyl iron/Fe 3 O 4 (FCI/Fe 3 O 4 ) composites with enhanced microwave absorption properties were prepared by a direct and flexible surface oxidation technique. The phase structures, morphology, magnetic properties, frequency-dependent electromagnetic and microwave absorption properties of the composites were investigated. The measurement results showed that lower permittivity as well as modest permeability was obtained by the FCI/Fe 3 O 4 composites. The calculated microwave absorption properties indicated that enhanced absorption efficiency and broader absorption band were obtained by the FCI/Fe 3 O 4 composite comparing with the FCI composite. The absorption frequency range with reflection loss (RL) below −5 dB of FCI/Fe 3 O 4 composites at reaction time of 90 min at thickness of 1.5 mm is 13.3 GHz from 4.7 to 18 GHz, while the bandwidth of the FCI composite is only 5.9 GHz from 2.6 to 8.5 GHz at the same thickness. Thus, such absorbers could act as effective and wide broadband microwave absorbers in the GHz range.

  7. Evaluation of iron bioavailability in a mixture of cereals, seeds, and grains ("Human Ration"

    Directory of Open Access Journals (Sweden)

    Bárbara Nery Enes

    2014-03-01

    Full Text Available Iron bioavailability was evaluated in three mixtures of cereals, seeds, and grains ("Human Ration": light, regular, and homemade provided to rats. The animals received an iron depletion diet for 21 days, followed by a repletion diet containing 12 mg·kg-1 of iron for 14 days. The hemoglobin regeneration efficiency and the relative biological value did not differ between the light mixture and control group. The iron bioavailability of the light mixture of cereals, seeds, and grains and the control group were 99.99±27.62 and 80.02±36.63, respectively, while the regular and homemade mixtures of cereals, seeds, and grains showed lower iron bioavailability, 50.12±35.53 and 66.66±15.44, respectively; the iron content of the diet with light cereal mixture light was statistically similar to that of the control (ferrous sulfate 99.99±27.62. The high content of tannin (202.81±19.53 mg·100-1 in the diet with the regular cereal mixture may have contributed to its low iron bioavailability. The higher intake of soluble fiber by the animals fed the light mixture (21.15±0.92 g was moderately correlated (r=0.5712, p=0.0018 with the concentration of propionate in the caecal bulk (65.49±11.08 µmol/g. The short chain fatty acids produced by soluble fiber fermentation, associated with the low-content of tannin may have improved iron solubility and absorption in the light cereal mixture diet. The iron bioavailability in the light mixture of cereals, seeds, and grains was similar to that of ferrous sulfate.

  8. Diurnal variations in iron concentrations and expression of genes involved in iron absorption and metabolism in pigs.

    Science.gov (United States)

    Zhang, Yiming; Wan, Dan; Zhou, Xihong; Long, Ciming; Wu, Xin; Li, Lan; He, Liuqin; Huang, Pan; Chen, Shuai; Tan, Bie; Yin, Yulong

    2017-09-02

    Diurnal variations in serum iron levels have been well documented in clinical studies, and serum iron is an important diagnostic index for iron-deficiency anemia. However, the underlying mechanism of dynamic iron regulation in response to the circadian rhythm is still unclear. In this study, we investigated daily variations in iron status in the plasma and liver of pigs. The transcripts encoding key factors involved in iron uptake and homeostasis were evaluated. The results showed that iron levels in the plasma and liver exhibited diurnal rhythms. Diurnal variations were also observed in transcript levels of divalent metal transporter 1 (DMT1), membrane-associated ferric reductase 1 (DCYTB), and transferrin receptor (TfR) in the duodenum and jejunum, as well as hepcidin (HAMP) and TfR in the liver. Moreover, the results showed a network in which diurnal variations in systemic iron levels were tightly regulated by hepcidin and Tf/TfR via DCYTB and DMT1. These findings provide new insights into circadian iron homeostasis regulation. The diurnal variations in serum iron levels may also have pathophysiological implications for clinical diagnostics related to iron deficiency anemia in pigs. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Bioavailability and the mechanisms of intestinal absorption of iron from ferrous ascorbate and ferric polymaltose in experimental animals

    International Nuclear Information System (INIS)

    Johnson, G.; Jacobs, P.

    1990-01-01

    The comparative bioavailability from matching quantities of iron in the form of ferrous ascorbate or ferric polymaltose was defined in rats. Studies were carried out in the intact animals under basal conditions and also when requirements for this metal were either increased or decreased by manipulating stores or erythropoietic activity. No significant difference was found in the total quantity of iron absorbed from either salt or complex under any of these circumstances, suggesting that the mucosal mechanism regulating the overall process was common to both. However, the rate of transfer from the lumen into portal blood was distinctive, reaching a maximum with salt at 30 min compared to 24 h for the complex. To explore the possibility that iron from the two sources was initially handled by different subcellular pathways, the radiolabeled compounds were instilled into loops of bowel that had been isolated between ligatures in vivo. Enterocytes were harvested and fractionated, and incorporation into ferritin and transferrin was determined using RIA. From salt, iron appeared rapidly in duodenal but not ileal ferritin, whereas mucosal transferrin increased under conditions of stimulated absorption, suggesting that this protein may act as a shuttle for the metal. In contrast, iron from polymaltose showed a cumulative incorporation into duodenal ferritin over time that correlated with iron absorption, defined by the appearance of radiolabel in the serum and in the carcass; a similar pattern was demonstrable in ileal mucosal cells. Conversely, binding of iron to transferrin was minimal. No iron polymaltose was found within the mucosal cells. It is suggested that the low rate of iron transfer from this ferric complex may reflect its extracellular breakdown in the lumen of the gastrointestinal tract

  10. Absorption and metabolic fate of bioactive dietary benzoxazinoids in humans

    DEFF Research Database (Denmark)

    Adhikari, Khem B; Laursen, Bente B; Gregersen, Per L

    2013-01-01

    benzoxazinoids with abundant HBOA-Glc (219 nmol × μmol−1 of creatinine). The sulfate and glucuronide conjugates of 2-hydroxy-1,4-benzoxazin-3-one (HBOA) and 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) were detected in plasma and urine, indicating substantial phase II metabolism. Direct absorption of lactam......Scope Benzoxazinoids, which are natural compounds recently identified in mature whole grain cereals and bakery products, have been suggested to have a range of pharmacological properties and health-protecting effects. There are no published reports concerned with the absorption and metabolism...... of bioactive benzoxazinoids in humans. Methods and results The absorption, metabolism, and excretion of ten different dietary benzoxazinoids were examined by LC-MS/MS by analyzing plasma and urine from 20 healthy human volunteers after daily intake of 143 μmol of total benzoxazinoids from rye bread and rye...

  11. Aluminum stimulates uptake of non-transferrin bound iron and transferrin bound iron in human glial cells

    International Nuclear Information System (INIS)

    Kim, Yongbae; Olivi, Luisa; Cheong, Jae Hoon; Maertens, Alex; Bressler, Joseph P.

    2007-01-01

    Aluminum and other trivalent metals were shown to stimulate uptake of transferrin bound iron and nontransferrin bound iron in erytholeukemia and hepatoma cells. Because of the association between aluminum and Alzheimer's Disease, and findings of higher levels of iron in Alzheimer's disease brains, the effects of aluminum on iron homeostasis were examined in a human glial cell line. Aluminum stimulated dose- and time-dependent uptake of nontransferrin bound iron and iron bound to transferrin. A transporter was likely involved in the uptake of nontransferrin iron because uptake reached saturation, was temperature-dependent, and attenuated by inhibitors of protein synthesis. Interestingly, the effects of aluminum were not blocked by inhibitors of RNA synthesis. Aluminum also decreased the amount of iron bound to ferritin though it did not affect levels of divalent metal transporter 1. These results suggest that aluminum disrupts iron homeostasis in Brain by several mechanisms including the transferrin receptor, a nontransferrin iron transporter, and ferritin

  12. Determining the Effect of Environmental Conditions on Iron Corrosion by Atomic Absorption

    Science.gov (United States)

    Malel, Esteban; Shalev, Deborah E.

    2013-01-01

    Iron corrosion is a complex process that occurs when iron is exposed to oxygen and humidity and is exacerbated by the presence of chloride ions. The deterioration of iron structures or other components can be costly to society and is usually evaluated by following the properties of the corroding material. Here, the iron ions released into solution…

  13. Ferric reductase activity of low molecular weight human milk fraction is associated with enhanced iron solubility and uptake in Caco-2 cells.

    Science.gov (United States)

    Pullakhandam, Raghu; Nair, Madhavan Krishnapillai; Kasula, Sunanda; Kilari, Sreenivasulu; Thippande, Tippeswamy Gowda

    2008-09-19

    It is known that the fractional absorption of extrinsic iron from human milk is higher in infants and adults. A low molecular weight milk fraction has been proposed to increase the bioavailability of iron from human milk. Nevertheless, the mechanisms remained elusive. Here in we demonstrate ferric reductase activity (Km7.73x10(-6)M) in low molecular weight human milk fraction (10kF, filtrate derived from ultra filtration of milk whey through 10kDa cutoff membrane), which increased ferric iron solubility and iron uptake in Caco-2 cells. The 10kF fraction was as effective as ascorbic acid (1:20 iron to ascorbic acid) in increasing the ferric iron solubility and uptake in Caco-2 cells. Further, gel filtration chromatography on peptide column led to co-elution of ferric reductase and iron solubilization activities at an apparent molecular mass of iron in Caco-2 cells. Thus, it is concluded that human milk possesses ferric reductase activity and is associated with ferric iron solubilization and enhanced absorption.

  14. Normal iron absorption determined by means of whole body counting and red cell incorporation of 59Fe

    International Nuclear Information System (INIS)

    Larsen, L.; Milman, N.

    1977-01-01

    Gastrointestinal iron absorption was measured in 27 normal subjects (19 females and 8 males) by means of whole body counting. Whole body retention 14 days after oral administration of 10μCi 59 Fe together with a carrier dose of 9.9 mg Fe 2+ (as sulphate), was used as an expression of absorption. The percentage incorporation in the total erythrocyte mass of administered 59 Fe (erythrocyte incorporation) and of absorbed 59 Fe (red cell utilization) was also estimated. Geometric mean iron absorption was 8.3+-2.1 (SD% in females, 9.1+-2.2 % in males and 8.5+-2.1 % in the entire series. The difference between males and females was not significant. Erythrocyte incorporation was 7.7+-2.2 (SD) % (geometric mean) in the entire series and the correlation between iron absorption and erythrocyte incorporation was highly significant (r = 0.96,P < 0.001). Red cell utilization averaged 92.9 +- 4.0 (SEM)% (arithmetic mean) in the entire series. (author)

  15. Different behaviour of 63Ni and 59Fe during absorption in iron-deficient and iron-adequate jejunal rat segments ex vivo

    International Nuclear Information System (INIS)

    Mueller-Fassbender, M.; Elsenhans, B.; McKie, A.T.; Schuemann, K.

    2003-01-01

    Nickel exhibits low oral toxicity. It shares the absorptive pathways for iron, though there are substantial quantitative differences in handling of both metals. To analyse these differences more closely, jejunal segments from iron-deficient and iron-adequate rats were luminally perfused ex vivo with 59 Fe and 63 Ni at six different concentrations (1-500 μmo1/l) under steady state conditions. 59 Fe over-all absorption increased 2.0-4.6-fold in iron-deficiency at luminal concentrations between 1 and 100 μmol/l, while 63 Ni absorption increased to a much lower extent (2.6-fold at 1 μmol/l and 1.5-fold at higher luminal concentrations). Moreover, there was a 5-7-fold higher concentration for 63 Ni in the jejunal tissue than in the absorbate at luminal concentrations above 50 μmol/l which was not observed at 1 μmol 63 Ni/l and not for 59 Fe. 63 Ni tissue load showed a linear and a saturable fraction. In iron-deficiency the saturable 63 Ni fraction increased 4-fold as compared to only 1.5-fold increments for 59 Fe. Moreover, a substantially higher share of 63 Ni was retained in the jejunal tissue at high as compare to low luminal concentrations after perfusion had been continued without luminal radioactivity. This was not found for 59 Fe and suggests a concentration-dependent block of 63 Ni export across the enterocytes' basolateral membrane. To explain these results one may speculate that 63 Ni may bind more tightly to tissue ligands than 59 Fe due to the higher thermodynamic and kinetic stability of nickel complexes. In particular, nickel may bind to a basolateral population of metal carriers and block its own basolateral transfer in a concentration-dependent manner. Tight 63 Ni binding to non-specific jejunal ligands is responsible for the unaltered high linear fraction of jejunal 63 Ni load in iron-deficient and iron-adequate segments. Binding of 63 Ni to food and tissue ligands in the small intestine may, thus, be a likely explanation for the low oral nickel

  16. Microwave absorption properties of the core/shell-type iron and nickel nanoparticles

    International Nuclear Information System (INIS)

    Lu, B.; Dong, X.L.; Huang, H.; Zhang, X.F.; Zhu, X.G.; Lei, J.P.; Sun, J.P.

    2008-01-01

    Iron (Fe) and nickel (Ni) nanoparticles were prepared by the DC arc-discharge method in a mixture of hydrogen and argon gases, using bulk metals as the raw materials. The microstructure of core/shell (metal/metal oxide) in nanoparticle formed after in situ passivation process. The complex electromagnetic parameters (permittivity ε r =ε r ' +iε r '' and permeability μ r =μ r ' +iμ r '' ) of the paraffin-mixed nanocomposite samples (paraffin:nanoparticles=1:1 in mass ratio) were measured in the frequency range of 2-18 GHz. The polarization mechanisms of the space charge and dipole coexist in both the Fe and Ni nanoparticles. The orientational polarization is a particular polarization for Fe nanoparticles and brings a relatively higher dielectric loss. Natural resonance is the main reason for magnetic loss and the corresponding frequencies are 11.6 and 5.2 GHz for the Fe and Ni nanoparticles, respectively. The paraffin composite with Fe nanoparticles provided excellent microwave absorption properties (reflection loss <-20 dB) in the range 6.8-16.6 GHz over the absorber thickness of 1.1-2.3 mm

  17. Speciation of iron (II) and (III) by using solvent extraction and flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Yaman, Mehmet; Kaya, Gokce

    2005-01-01

    A method for speciation, preconcentration and separation of Fe 2+ and Fe 3+ in different matrices was developed using solvent extraction and flame atomic absorption spectrometry. PAN as complexing reagent for Fe 2+ and chloroform as organic solvent were used. The complex of Fe 2+ -PAN was extracted into chloroform phase in the pH range of 0.75-4.0 and Fe 3+ remains in water phase in the pH range 0.75-1.25. The optimum conditions for maximum recovery of Fe 2+ and minimum recovery of Fe 3+ were determined as pH = 1, the stirring time of 20 min, the PAN amount of 0.5 mg and chloroform volume of 8 mL. The developed method was applied to the determination of Fe 2+ and Fe 3+ in tea infusion, fruit juice, cola and pekmez. It is seen that there is high bioavailable iron (Fe 2+ ) in pekmez. The developed method is sensitive, simple and need the shorter time in comparison with other similar studies

  18. Observation of electromagnetically induced transparency and absorption in Yttrium Iron Garnet loaded split ring resonator

    Science.gov (United States)

    Tay, Z. J.; Soh, W. T.; Ong, C. K.

    2018-04-01

    In this paper, we propose a new method of controlling microwave transmission from Electromagnetically Induced Absorption (EIA) to Electromagnetically Induced Transparency (EIT). EIA describes the state where the system strongly absorbs microwaves, whereas EIT describes the state in which the system is transparent to microwaves. Control is achieved via coupling of the 3 GHz photon mode of a metamaterial Split Ring Resonator (SRR) to the spin wave magnon modes of a Yttrium Iron Garnet (YIG) bulk. The system is described by a 2-body interaction matrix with an additional fitting parameter τ which takes into account the fact that the microstrip feed line could excite the SRR as well as the YIG. The parameter τ reveals the effect of geometry and shielding on the coupling behaviour and gives rise to unique physics. In low τ (τ ⩽ 2) configurations, only EIT is reported. However, in high τ (τ ≈ 10) configurations, EIA is reported. Furthermore, we report that the system can be easily changed from a low τ to high τ configuration by shielding the SRR from the microstrip with a thin metal piece. Varying the τ parameter through shielding is thus proposed as a new method of controlling the microwave transmission at the coupling region.

  19. Microwave absorption properties of the core/shell-type iron and nickel nanoparticles

    Science.gov (United States)

    Lu, B.; Dong, X. L.; Huang, H.; Zhang, X. F.; Zhu, X. G.; Lei, J. P.; Sun, J. P.

    Iron (Fe) and nickel (Ni) nanoparticles were prepared by the DC arc-discharge method in a mixture of hydrogen and argon gases, using bulk metals as the raw materials. The microstructure of core/shell (metal/metal oxide) in nanoparticle formed after in situ passivation process. The complex electromagnetic parameters (permittivity ɛ=ɛr'+iɛr″ and permeability μ=μr'+iμr″) of the paraffin-mixed nanocomposite samples (paraffin:nanoparticles=1:1 in mass ratio) were measured in the frequency range of 2-18 GHz. The polarization mechanisms of the space charge and dipole coexist in both the Fe and Ni nanoparticles. The orientational polarization is a particular polarization for Fe nanoparticles and brings a relatively higher dielectric loss. Natural resonance is the main reason for magnetic loss and the corresponding frequencies are 11.6 and 5.2 GHz for the Fe and Ni nanoparticles, respectively. The paraffin composite with Fe nanoparticles provided excellent microwave absorption properties (reflection loss <-20 dB) in the range 6.8-16.6 GHz over the absorber thickness of 1.1-2.3 mm.

  20. Facile preparation and enhanced microwave absorption properties of flake carbonyl iron/Fe{sub 3}O{sub 4} composite

    Energy Technology Data Exchange (ETDEWEB)

    Min, Dandan, E-mail: mdd4776@126.com; Zhou, Wancheng; Luo, Fa; Zhu, Dongmei

    2017-08-01

    Highlights: • Flake carbonyl iron/Fe{sub 3}O{sub 4} composites were prepared by surface oxidation technique. • Lower permittivity and modest permeability was obtained by the FCI/Fe{sub 3}O{sub 4} composites. • Enhanced absorption efficiency and broader absorption band were obtained. - Abstract: Flake carbonyl iron/Fe{sub 3}O{sub 4} (FCI/Fe{sub 3}O{sub 4}) composites with enhanced microwave absorption properties were prepared by a direct and flexible surface oxidation technique. The phase structures, morphology, magnetic properties, frequency-dependent electromagnetic and microwave absorption properties of the composites were investigated. The measurement results showed that lower permittivity as well as modest permeability was obtained by the FCI/Fe{sub 3}O{sub 4} composites. The calculated microwave absorption properties indicated that enhanced absorption efficiency and broader absorption band were obtained by the FCI/Fe{sub 3}O{sub 4} composite comparing with the FCI composite. The absorption frequency range with reflection loss (RL) below −5 dB of FCI/Fe{sub 3}O{sub 4} composites at reaction time of 90 min at thickness of 1.5 mm is 13.3 GHz from 4.7 to 18 GHz, while the bandwidth of the FCI composite is only 5.9 GHz from 2.6 to 8.5 GHz at the same thickness. Thus, such absorbers could act as effective and wide broadband microwave absorbers in the GHz range.

  1. Quantitation of small intestinal permeability during normal human drug absorption

    OpenAIRE

    Levitt, David G

    2013-01-01

    Background Understanding the quantitative relationship between a drug?s physical chemical properties and its rate of intestinal absorption (QSAR) is critical for selecting candidate drugs. Because of limited experimental human small intestinal permeability data, approximate surrogates such as the fraction absorbed or Caco-2 permeability are used, both of which have limitations. Methods Given the blood concentration following an oral and intravenous dose, the time course of intestinal absorpti...

  2. Effect of Gamma Radiation on Absorption of Light in Potassium-Aluminoborate Glasses with Additions of Iron Oxide

    Science.gov (United States)

    Ibragimova, E. M.; Salakhitdinov, A. N.; Salakhitdinova, M. K.; Yusupov, A. A.

    2018-05-01

    The effect of radiation on the absorption of light by potassium-alumina-borate glasses with various concentrations of iron additions and various thicknesses was investigated. It was shown that in contrast to samples of small thickness (1 mm) a bleaching effect was observed in the samples with a thickness of 8 mm. A possible mechanism involving the formation of nanostructured units is proposed for the observed effect.

  3. Determination of calcium, copper, chromium, iron, magnesium, manganese, potassium, sodium and zinc in ethanol by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Fernandes, E.A.N.

    1981-01-01

    The direct determinacao of calcium, copper, chomium, iron, magnesium, manganese, potassium, sodium and zinc in ethanol by atomic absorption spectrometry with, air-acetylene flame is proposed. Effects of fuel/oxidant ratio, burner height and water content in the samples were investigated in detail. The method allows the determition of the elements with good precision (r.s.d. -1 for the elements tested. (author) [pt

  4. Absorption of environmental polonium-210 by the human gut

    International Nuclear Information System (INIS)

    Hunt, G.J.; Allington, D.J.

    1993-01-01

    Current values for the gut absorption factor of plutonium- 210 ( 210 Po) are based on very few human data, yet the dose due to 210 Po is an important component of the dose to man through food as a result of natural sources of radiation. In this study, three male and three female adult volunteers ate supplies of brown crab meat containing natural concentrations of 210 Po, which are analysed from sub-samples. Daily urine and faecal samples, taken for 3 days before and up to 3 weeks after ingestion, were also analysed. Values of apparent absorption were derived from the faecal measurements; estimates of the true absorption were derived taking account of endogenous faecal excretion on the basis of existing data for intravenous administration. The results appear to suggest that the gut absorption factor in current use for 210 Po (in connection with ingestion in food) should be increased from 0.1-03 to about 0.8. The implications for estimates of dose due to this exposure pathway are noted. (author)

  5. Absorption of environmental polonium-210 by the human gut

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, G J; Allington, D J [Ministry of Agriculture, Fisheries and Food, Lowestoft (United Kingdom). Fisheries Radiobiological Lab.

    1993-06-01

    Current values for the gut absorption factor of plutonium- 210 ([sup 210]Po) are based on very few human data, yet the dose due to [sup 210]Po is an important component of the dose to man through food as a result of natural sources of radiation. In this study, three male and three female adult volunteers ate supplies of brown crab meat containing natural concentrations of [sup 210]Po, which are analysed from sub-samples. Daily urine and faecal samples, taken for 3 days before and up to 3 weeks after ingestion, were also analysed. Values of apparent absorption were derived from the faecal measurements; estimates of the true absorption were derived taking account of endogenous faecal excretion on the basis of existing data for intravenous administration. The results appear to suggest that the gut absorption factor in current use for [sup 210]Po (in connection with ingestion in food) should be increased from 0.1-03 to about 0.8. The implications for estimates of dose due to this exposure pathway are noted. (author).

  6. Alternating magnetic field energy absorption in the dispersion of iron oxide nanoparticles in a viscous medium

    Energy Technology Data Exchange (ETDEWEB)

    Smolkova, Ilona S. [Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, nad Ovcirnou 3685, 760 01 Zlin (Czech Republic); Polymer Centre, Faculty of Technology, Tomas Bata University in Zlin, T.G. Masaryk Sq. 275, 762 72 Zlin (Czech Republic); Kazantseva, Natalia E., E-mail: nekazan@yahoo.com [Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, nad Ovcirnou 3685, 760 01 Zlin (Czech Republic); Babayan, Vladimir; Smolka, Petr; Parmar, Harshida; Vilcakova, Jarmila [Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, nad Ovcirnou 3685, 760 01 Zlin (Czech Republic); Schneeweiss, Oldrich; Pizurova, Nadezda [Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, 616 62 Brno (Czech Republic)

    2015-01-15

    Magnetic iron oxide nanoparticles were obtained by a coprecipitation method in a controlled growth process leading to the formation of uniform highly crystalline nanoparticles with average size of 13 nm, which corresponds to the superparamagnetic state. Nanoparticles obtained are a mixture of single-phase nanoparticles of magnetite and maghemite as well as nanoparticles of non-stoichiometric magnetite. The subsequent annealing of nanoparticles at 300 °C in air during 6 h leads to the full transformation to maghemite. It results in reduced value of the saturation magnetization (from 56 emu g{sup −1} to 48 emu g{sup −1}) but does not affect the heating ability of nanoparticles. A 2–7 wt% dispersion of as-prepared and annealed nanoparticles in glycerol provides high heating rate in alternating magnetic fields allowed for application in magnetic hyperthermia; however the value of specific loss power does not exceed 30 W g{sup −1}. This feature of heat output is explained by the combined effect of magnetic interparticle interactions and the properties of the carrier medium. Nanoparticles coalesce during the synthesis and form aggregates showing ferromagnetic-like behavior with magnetization hysteresis, distinct sextets on Mössbauer spectrum, blocking temperature well about room temperature, which accounts for the higher energy barrier for magnetization reversal. At the same time, low specific heat capacity of glycerol intensifies heat transfer in the magnetic dispersion. However, high viscosity of glycerol limits the specific loss power value, since predominantly the Neel relaxation accounts for the absorption of AC magnetic field energy. - Highlights: • Mixed phase iron oxide magnetic nanoparticles were obtained by coprecipitation. • A part of nanoparticles was annealed at 300 °C to achieve the single-phase γ-Fe{sub 2}O{sub 3}. • Nanoparticles revealed ferromagnetic-like behavior due to interparticle interactions. • Nanoparticles glycerol

  7. Copper Deficiency Leads to Anemia, Duodenal Hypoxia, Upregulation of HIF-2α and Altered Expression of Iron Absorption Genes in Mice

    Science.gov (United States)

    Matak, Pavle; Zumerle, Sara; Mastrogiannaki, Maria; El Balkhi, Souleiman; Delga, Stephanie; Mathieu, Jacques R. R.; Canonne-Hergaux, François; Poupon, Joel; Sharp, Paul A.; Vaulont, Sophie; Peyssonnaux, Carole

    2013-01-01

    Iron and copper are essential trace metals, actively absorbed from the proximal gut in a regulated fashion. Depletion of either metal can lead to anemia. In the gut, copper deficiency can affect iron absorption through modulating the activity of hephaestin - a multi-copper oxidase required for optimal iron export from enterocytes. How systemic copper status regulates iron absorption is unknown. Mice were subjected to a nutritional copper deficiency-induced anemia regime from birth and injected with copper sulphate intraperitoneally to correct the anemia. Copper deficiency resulted in anemia, increased duodenal hypoxia and Hypoxia inducible factor 2α (HIF-2α) levels, a regulator of iron absorption. HIF-2α upregulation in copper deficiency appeared to be independent of duodenal iron or copper levels and correlated with the expression of iron transporters (Ferroportin - Fpn, Divalent Metal transporter – Dmt1) and ferric reductase – Dcytb. Alleviation of copper-dependent anemia with intraperitoneal copper injection resulted in down regulation of HIF-2α-regulated iron absorption genes in the gut. Our work identifies HIF-2α as an important regulator of iron transport machinery in copper deficiency. PMID:23555700

  8. Bioavailability of iron and zinc from human diets: Nutrient delivery technology salt fortification in human nutrition

    International Nuclear Information System (INIS)

    Raghuramulu, N.

    1992-01-01

    Iodine deficiency disorders (IDD), iron deficiency anaemia(IDA) and zinc deficiency are common problems in India. The discussions in this paper centers on the selection of the vehicles which could be used to successfully deliver essential nutrients into the daily diet of the general population of india and the identification of compounds which inhibit the intestinal absorption of zinc. 40 refs, 11 tabs

  9. Determination of iron absorption and excretion by whole-body counting; Determination de l'absorption et de l'excretion du fer par la methode de comptage global humain

    Energy Technology Data Exchange (ETDEWEB)

    Hollard, D; Benabid, Y; Berard, M; Bonnin, J; Darnault, J; Millet, M [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    Using a whole-body counter, the authors have studied {sup 59}Fe absorption and loss in 8 normal subjects and in 30 iron deficient patients. Results showed that whole-body counting provided an excellent and simple method for iron retention measurements, obviating many inaccuracies of previous technic. Normal absorption of radio iron with this procedure has ranged from 9 per cent to 20 per cent of the administered tracer in normal subjects, with a mean of 15 per cent. A significant increase in {sup 59}Fe absorption was noted in 21 iron-deficient patients in whom the retention ranged from 40 to 100 per cent. However, 3 iron-deficient patients were found to have low absorption, and their severe iron deficiency could be correlated with this defect in absorption. This method permits also the determination of the rate of iron excretion during the following months and therefore the study of the mechanism of some pathological loss. (authors) [French] L'utilisation de la methode de comptage humain global a permis aux auteurs d'etudier l'absorption et l'excretion du fer-59 chez 8 sujets temoins et 30 sujets hyposideremiques. Les resultats montrent que cette technique simple et directe offre de nombreux avantages sur les methodes employees jusqu'a maintenant pour cette determination. La valeur normale de l'absorption du fer chez les temoins est d'environ 15 pour cent de la dose ingeree. Ce chiffre est tres fortement augmente chez 21 sujets hyposideremiques, pouvant atteindre 100 pour cent de la dose ingeree. Par contre, pour 3 malades, cette absorption est si faible qu'elle suggere une carence par defaut d'absorption. Cette methode permet egalement de suivre l'excretion du fer au cours des mois qui suivent l'examen et de determiner le mecanisme de fuites anormales. (auteurs)

  10. Iron

    Science.gov (United States)

    Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

  11. Iron Bioavailability from Ferric Pyrophosphate in Extruded Rice Cofortified with Zinc Sulfate Is Greater than When Cofortified with Zinc Oxide in a Human Stable Isotope Study.

    Science.gov (United States)

    Hackl, Laura; Zimmermann, Michael B; Zeder, Christophe; Parker, Megan; Johns, Paul W; Hurrell, Richard F; Moretti, Diego

    2017-03-01

    Background: Extruded rice grains are often cofortified with iron and zinc. However, it is uncertain if the addition of zinc to iron-fortified rice affects iron absorption and whether this is zinc-compound specific. Objective: We investigated whether zinc, added as zinc oxide (ZnO) or zinc sulfate (ZnSO 4 ), affects human iron absorption from extruded rice fortified with ferric pyrophosphate (FePP). Methods: In 19 iron-depleted Swiss women (plasma ferritin ≤16.5 μ/L) aged between 20 and 39 y with a normal body mass index (in kg/m 2 ; 18.7-24.8), we compared iron absorption from 4 meals containing fortified extruded rice with 4 mg Fe and 3 mg Zn. Three of the meals contained extruded rice labeled with FePP ( 57 FePP): 1 ) 1 meal without added zinc ( 57 FePP-Zn), 2 ) 1 cofortified with ZnO ( 57 FePP+ZnO), and 3 ) 1 cofortified with ZnSO 4 ( 57 FePP+ZnSO 4 ). The fourth meal contained extruded rice without iron or zinc, extrinsically labeled with ferrous sulfate ( 58 FeSO 4 ) added as a solution after cooking. All 4 meals contained citric acid. Iron bioavailability was measured by isotopic iron ratios in red blood cells. We also measured relative in vitro iron solubility from 57 FePP-Zn, 57 FePP+ZnO, and 57 FePP+ZnSO 4 expressed as a fraction of FeSO 4 solubility. Results: Geometric mean fractional iron absorption (95% CI) from 57 FePP+ZnSO 4 was 4.5% (3.4%, 5.8%) and differed from 57 FePP+ZnO (2.7%; 1.8%, 4.1%) ( P iron bioavailabilities compared with 58 FeSO 4 were 62%, 57%, and 38% from 57 FePP+ZnSO 4 , 57 FePP-Zn, and 57 FePP+ZnO, respectively. In vitro solubility from 57 FePP+ZnSO 4 differed from that of 57 FePP-Zn (14.3%; P iron-depleted women, iron absorption from FePP-fortified extruded rice cofortified with ZnSO 4 was 1.6-fold (95% CI: 1.4-, 1.9-fold) that of rice cofortified with ZnO. These findings suggest that ZnSO 4 may be the preferable zinc cofortificant for optimal iron bioavailability of iron-fortified extruded rice. This trial was registered at

  12. Nicotianamine, a novel enhancer of rice iron bioavailability to humans.

    Directory of Open Access Journals (Sweden)

    Luqing Zheng

    Full Text Available BACKGROUND: Polished rice is a staple food for over 50% of the world's population, but contains little bioavailable iron (Fe to meet human needs. Thus, biofortifying the rice grain with novel promoters or enhancers of Fe utilization would be one of the most effective strategies to prevent the high prevalence of Fe deficiency and iron deficiency anemia in the developing world. METHODOLOGY/PRINCIPAL FINDINGS: We transformed an elite rice line cultivated in Southern China with the rice nicotianamine synthase gene (OsNAS1 fused to a rice glutelin promoter. Endosperm overexpression of OsNAS1 resulted in a significant increase in nicotianamine (NA concentrations in both unpolished and polished grain. Bioavailability of Fe from the high NA grain, as measured by ferritin synthesis in an in vitro Caco-2 cell model that simulates the human digestive system, was twice as much as that of the control line. When added at 1:1 molar ratio to ferrous Fe in the cell system, NA was twice as effective when compared to ascorbic acid (one of the most potent known enhancers of Fe bioavailability in promoting more ferritin synthesis. CONCLUSIONS: Our data demonstrated that NA is a novel and effective promoter of iron utilization. Biofortifying polished rice with this compound has great potential in combating global human iron deficiency in people dependent on rice for their sustenance.

  13. Nonheme-iron absorption from a phytate-rich meal is increased by the addition of small amounts of pork meat

    DEFF Research Database (Denmark)

    Boech, S.B.; Hansen, M.; Bukhave, Klaus

    2003-01-01

    of small amounts of meat on nonheme-iron absorption from a meal presumed to have low iron bioavailability. Design: Forty-five healthy women with a mean (+/-SD) age of 24 +/- 3 y were randomly assigned to I of 3 groups, each of which was served (A) a basic meal (rice, tomato sauce, pea puree, and a wheat...

  14. Near infrared laser penetration and absorption in human skin

    Science.gov (United States)

    Nasouri, Babak; Murphy, Thomas E.; Berberoglu, Halil

    2014-02-01

    For understanding the mechanisms of low level laser/light therapy (LLLT), accurate knowledge of light interaction with tissue is necessary. In this paper, we present a three dimensional, multi-layer Monte Carlo simulation tool for studying light penetration and absorption in human skin. The skin is modeled as a three-layer participating medium, namely epidermis, dermis, and subcutaneous, where its geometrical and optical properties are obtained from the literature. Both refraction and reflection are taken into account at the boundaries according to Snell's law and Fresnel relations. A forward Monte Carlo method was implemented and validated for accurately simulating light penetration and absorption in absorbing and anisotropically scattering media. Local profiles of light penetration and volumetric absorption densities were simulated for uniform as well as Gaussian profile beams with different spreads at 155 mW average power over the spectral range from 1000 nm to 1900 nm. The results show the effects of beam profiles and wavelength on the local fluence within each skin layer. Particularly, the results identify different wavelength bands for targeted deposition of power in different skin layers. Finally, we show that light penetration scales well with the transport optical thickness of skin. We expect that this tool along with the results presented will aid researchers resolve issues related to dose and targeted delivery of energy in tissues for LLLT.

  15. Nonrandom distribution of iron in circulating human transferrin.

    Science.gov (United States)

    Zak, O; Aisen, P

    1986-07-01

    By combining the urea gel electrophoresis technique of Makey and Seal with Western immunoblotting, a method has been developed for analyzing the distribution of iron between the two sites of circulating human transferrin. The new method avoids exposure of samples to a nonphysiologic pH that may promote removal or redistribution of iron from the protein; this facilitates examination of multiple samples at one time. Analysis of 21 freshly drawn specimens from normal human subjects confirms previous reports that iron is not randomly distributed in the specific sites of transferrin. Rather, there is a considerable range in the ratio of occupancies of N-terminal and C-terminal sites (N:C ratio), from 0.31 to 6.87 in the present study, with the N-terminal site predominantly occupied in most subjects. The N:C ratio correlates modestly with serum iron concentration (r = .54). Possible flaws in studies indicating a random occupancy of the specific sites of circulating transferrin may lie in the low pH to which samples may be exposed during procedures based on isoelectric focusing or in drawing inferences from data considering only total monoferric transferrin rather than the two distinguishable monoferric species.

  16. Preparation and characterization of novel glass–ceramic tile with microwave absorption properties from iron ore tailings

    International Nuclear Information System (INIS)

    Yao, Rui; Liao, SongYi; Dai, ChangLu; Liu, YuChen; Chen, XiaoYu; Zheng, Feng

    2015-01-01

    A novel glass–ceramic tile consisting of one glass–ceramic layer (GC) attaining microwave absorption properties atop ceramic substrate was prepared through quench-heat treatment route derived from iron ore tailings (IOTs) and commercial raw materials (purity range 73–99%). X-ray diffraction (XRD), SEM, Energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), Physical property measurement system (PPMS) and Vector network analyzer (VNA) measurements were carried out to investigate phase, microstructure, magnetic and microwave absorption aspects of the glass–ceramic layer. Roughly 80.6±1.7 wt% borosilicate glass and 19.4±1.7 wt% spinel ferrite with chemical formula of (Zn 2+ 0.17 Fe 3+ 0.83 )[Fe 3+ 1.17 Fe 2+ 0.06 Ni 2+ 0.77 ]O 4 were found among the tested samples. Absorption of Electromagnetic wave by 3 mm thick glass–ceramic layer at frequency of 2–18 GHz reached peak reflection loss (RL) of −17.61 dB (98.27% microwave absorption) at 10.31 GHz. Altering the thickness of the glass–ceramic layer can meet the requirements of different level of microwave absorption. - Highlights: • Iron ore tailings (IOTs) have been used as one of the main raw materials. • Glass–ceramic tile contains spinel ferrite has been prepared. • The cation distribution of the spinel ferrite has been calculated. • The intrinsic complex permeability and permittivity have been evaluated

  17. Preparation and characterization of novel glass–ceramic tile with microwave absorption properties from iron ore tailings

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Rui; Liao, SongYi [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Dai, ChangLu [Guangdong Bode Fine Building Material Co. Ltd., Foshan 528000 (China); Liu, YuChen; Chen, XiaoYu [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Zheng, Feng, E-mail: fzheng@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Phase diagrams and materials design center, Central South University, Changsha 410083 (China)

    2015-03-15

    A novel glass–ceramic tile consisting of one glass–ceramic layer (GC) attaining microwave absorption properties atop ceramic substrate was prepared through quench-heat treatment route derived from iron ore tailings (IOTs) and commercial raw materials (purity range 73–99%). X-ray diffraction (XRD), SEM, Energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), Physical property measurement system (PPMS) and Vector network analyzer (VNA) measurements were carried out to investigate phase, microstructure, magnetic and microwave absorption aspects of the glass–ceramic layer. Roughly 80.6±1.7 wt% borosilicate glass and 19.4±1.7 wt% spinel ferrite with chemical formula of (Zn{sup 2+}{sub 0.17}Fe{sup 3+}{sub 0.83})[Fe{sup 3+}{sub 1.17}Fe{sup 2+}{sub 0.06}Ni{sup 2+}{sub 0.77}]O{sub 4} were found among the tested samples. Absorption of Electromagnetic wave by 3 mm thick glass–ceramic layer at frequency of 2–18 GHz reached peak reflection loss (RL) of −17.61 dB (98.27% microwave absorption) at 10.31 GHz. Altering the thickness of the glass–ceramic layer can meet the requirements of different level of microwave absorption. - Highlights: • Iron ore tailings (IOTs) have been used as one of the main raw materials. • Glass–ceramic tile contains spinel ferrite has been prepared. • The cation distribution of the spinel ferrite has been calculated. • The intrinsic complex permeability and permittivity have been evaluated.

  18. Electron energy-loss spectroscopy characterization and microwave absorption of iron-filled carbon-nitrogen nanotubes

    International Nuclear Information System (INIS)

    Che Renchao; Liang Chongyun; Shi Honglong; Zhou Xingui; Yang Xinan

    2007-01-01

    Iron-filled carbon-nitrogen (Fe/CN x ) nanotubes and iron-filled carbon (Fe/C) nanotubes were synthesized at 900 deg. C through a pyrolysis reaction of ferrocene/acetonitrile and ferrocene/xylene, respectively. The differences of structure and composition between the Fe/CN x nanotubes and Fe/C nanotubes were investigated by transmission electron microscopy and electron energy-loss spectroscopy (EELS). It was found that the morphology of Fe/CN x nanotubes is more corrugated than that of the Fe/C nanotubes due to the incorporation of nitrogen. By comparing the Fe L 2,3 electron energy-loss spectra of Fe/CN x nanotubes to those of the Fe/C nanotubes, the electron states at the interface between Fe and the tubular wall of both Fe/CN x nanotubes and Fe/C nanotubes were investigated. At the boundary between Fe and the wall of a CN x nanotube, the additional electrons contributed from the doped 'pyridinic-like' nitrogen might transfer to the empty 3d orbital of the encapsulated iron, therefore leading to an intensity suppression of the iron L 2,3 edge and an intensity enhancement of the carbon K edge. However, such an effect could not be found in Fe/C nanotubes. Microwave absorption properties of both Fe/CN x and Fe/C nanocomposites at 2-18 GHz band were studied

  19. Determination of silver in fresh water by atomic absorption spectrometry following flotation preconcentration by iron(III) collectors

    Energy Technology Data Exchange (ETDEWEB)

    Cundeva, K.; Stafilov, T. [Institute of Chemistry, Faculty of Science, St. Cyril and Methodius University, Skopje (Yugoslavia)

    1997-08-01

    Colloid precipitate flotation of silver from fresh water is applied for preconcentration and separation. Optimal conditions using hydrated iron(III) oxide and iron(III) tetramethylenedithiocarbamate as collectors were investigated. Various factors affecting the silver recovery, including collector mass, nature of the supporting electrolyte, pH of the working medium, electrokinetic potential of the collector particle surfaces, type of surfactant, induction time etc., were checked. Within the optimal pH range (5.5-6.5) silver was separated quantitatively (94.9- 100.0%) with 30 mg Fe(III) as collector. The content of silver was determined by electrothermal atomic absorption spectrometry and compared to that from inductively coupled plasma-atomic emission spectrometry. The detection limit of silver by the method described is 0.01 {mu}g/L. (orig.) With 2 figs., 3 tabs.

  20. Human macrophage hemoglobin-iron metabolism in vitro

    International Nuclear Information System (INIS)

    Custer, G.; Balcerzak, S.; Rinehart, J.

    1982-01-01

    An entirely in vitro technique was employed to characterize hemoglobin-iron metabolism by human macrophages obtained by culture of blood monocytes and pulmonary alveolar macrophages. Macrophages phagocytized about three times as many erythrocytes as monocytes and six times as many erythrocytes as pulmonary alveolar macrophages. The rate of subsequent release of 59 Fe to the extracellular transferrin pool was two- to fourfold greater for macrophages as compared to the other two cell types. The kinetics of 59 Fe-transferrin release were characterized by a relatively rapid early phase (hours 1-4) followed by a slow phase (hours 4-72) for all three cell types. Intracellular movement of iron was characterized by a rapid shift from hemoglobin to ferritin that was complete with the onset of the slow phase of extracellular release. A transient increase in 59 Fe associated with an intracellular protein eluting with transferrin was also observed within 1 hour after phagocytosis. The process of hemoglobin-iron release to extracellular transferrin was inhibited at 4 degrees C but was unaffected by inhibitory of protein synthesis, glycolysis, microtubule function, and microfilament function. These data emphasize the rapidity of macrophage hemoglobin iron metabolism, provide a model for characterization of this process in vitro, and in general confirm data obtained utilizing in vivo animal models

  1. Iron deficiency up-regulates iron absorption from ferrous sulphate but not ferric pyrophosphate and consequently food fortification with ferrous sulphate has relatively greater efficacy in iron-deficient individuals

    NARCIS (Netherlands)

    Zimmermann, M.B.; Biebinger, R.; Egli, I.; Zeder, C.; Hurrell, R.F.

    2011-01-01

    Fe absorption from water-soluble forms of Fe is inversely proportional to Fe status in humans. Whether this is true for poorly soluble Fe compounds is uncertain. Our objectives were therefore (1) to compare the up-regulation of Fe absorption at low Fe status from ferrous sulphate (FS) and ferric

  2. Evaluation of iron transport from ferrous glycinate liposomes using ...

    African Journals Online (AJOL)

    2017-09-03

    Sep 3, 2017 ... Insufficient dietary intake and low iron bio- availability in foods ... pared with common iron supplements, iron liposomes can obviously ... to inhibit iron absorption in humans and in cell culture models11. ..... ical nutrition issues. The effects of .... of approximately 2-100 nm could play an active role in mediating ...

  3. Effects of proteins on absorption by the rat of iron from polymeric and low-molecular-weight iron species

    International Nuclear Information System (INIS)

    Berner, L.; Miller, D.

    1986-01-01

    To examine effects of proteins on Fe absorption from polymeric ferric hydroxides (polys) or low-molecular-weight complexes (LMW Fe), 2 studies were conducted. First, anemic rats were given 59 Fe-labeled polys or LMW Fe in the presence and absence of pepsin-digested soy protein isolate, casein, and BSA. The doses were introduced into ligated duodenal segments for 1 hr. Uptake into the carcass of 59 Fe from polys was doubled in the presence of BSA (7.8 vs 16.1%, p 59 Fe from LMW Fe was 7X greater than from polys; BSA and casein had no effect but soy depressed Fe uptake by almost 50% (57.4 vs 35.5%, p < .05). The second experiment repeated the first except that the proteins were not pepsin-digested and the doses were given by gastric intubation. All Fe, whether from polys or LMW Fe, was highly available (although in vitro digestions reveal that polys are not depolymerized to a large degree under simulated stomach conditions). Soy depressed Fe uptake from both sources (92.9 vs. 81.6%, LMW Fe and 85.4 vs 73.7%, polys) while casein and BSA had no effect. These results show: (1) BSA can depolymerize polys in the rat duodenum, thus enhancing absorption; (2) soy isolate generally depressed Fe uptake; and (3) the rat stomach appears to have an exceptional capacity for equalizing Fe sources

  4. Remote controlled capsules in human drug absorption (HDA) studies.

    Science.gov (United States)

    Wilding, Ian R; Prior, David V

    2003-01-01

    The biopharmaceutical complexity of today's new drug candidates provides significant challenges for pharmaceutical scientists in terms of both candidate selection and optimizing subsequent development strategy. In addition, life cycle management of marketed drugs has become an important income stream for pharmaceutical companies, but the selection of least risk/highest benefit strategies is far from simple. The proactive adoption of human drug absorption (HDA) studies using remote controlled capsules offers the pharmaceutical scientist significant guidance for planning a route through the maze of product development. This review examines the position of HDA studies in drug development, using a variety of case histories and an insightful update on remote controlled capsules to achieve site-specific delivery.

  5. In Rwandese Women with Low Iron Status, Iron Absorption from Low-Phytic Acid Beans and Biofortified Beans Is Comparable, but Low-Phytic Acid Beans Cause Adverse Gastrointestinal Symptoms.

    Science.gov (United States)

    Petry, Nicolai; Rohner, Fabian; Gahutu, Jean Bosco; Campion, Bruno; Boy, Erick; Tugirimana, Pierrot L; Zimmerman, Michael Bruce; Zwahlen, Christian; Wirth, James P; Moretti, Diego

    2016-05-01

    Phytic acid (PA) is a major inhibitor of iron bioavailability from beans, and high PA concentrations might limit the positive effect of biofortified beans (BBs) on iron status. Low-phytic acid (lpa) bean varieties could increase iron bioavailability. We set out to test whether lpa beans provide more bioavailable iron than a BB variety when served as part of a composite meal in a bean-consuming population with low iron status. Dietary iron absorption from lpa, iron-biofortified, and control beans (CBs) (regular iron and PA concentrations) was compared in 25 nonpregnant young women with low iron status with the use of a multiple-meal crossover design. Iron absorption was measured with stable iron isotopes. PA concentration in lpa beans was ∼10% of BBs and CBs, and iron concentration in BBs was ∼2- and 1.5-fold compared with CBs and lpa beans, respectively. Fractional iron absorption from lpa beans [8.6% (95% CI: 4.8%, 15.5%)], BBs [7.3% (95% CI: 4.0%, 13.4%)], and CBs [8.0% (95% CI: 4.4%, 14.6%)] did not significantly differ. The total amount of iron absorbed from lpa beans and BBs was 421 μg (95% CI: 234, 756 μg) and 431 μg (95% CI: 237, 786 μg), respectively, and did not significantly differ, but was >50% higher (P beans were hard to cook, and their consumption caused transient adverse digestive side effects in ∼95% of participants. Gel electrophoresis analysis showed phytohemagglutinin L (PHA-L) residues in cooked lpa beans. BBs and lpa beans provided more bioavailable iron than control beans and could reduce dietary iron deficiency. Digestive side effects of lpa beans were likely caused by PHA-L, but it is unclear to what extent the associated digestive problems reduced iron bioavailability. This trial was registered at clinicaltrials.gov as NCT02215278. © 2016 American Society for Nutrition.

  6. Absorption and Flux Density Measurements in an Iron Plug in R1

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Ragnar; Braun, Josef

    1958-11-15

    Thermal, epithermal and fast neutron fluxes have been measured in a 60 cm long, 'sliced' iron plug, which has been placed in the lower iron lid of the Swedish reactor R1. Au foils, Cu foils, Mn foils, P packets, Cu wires and small Fe cylinders have been used. The gamma flux has been determined with film dosimeters. The measurements have shown that only in the first centimeters of the iron is the activation determined by the thermal flux, which decreases with a relaxation length {lambda}= (1.51 {+-} 0.02) cm. The epithermal flux is entirely predominant already after 10 cm ( {lambda} = 16 cm). The epithermal neutron flux decreases even more slowly than the fast flux ({lambda} = 6.2 cm)

  7. Absorption and Flux Density Measurements in an Iron Plug in R1

    International Nuclear Information System (INIS)

    Nilsson, Ragnar; Braun, Josef

    1958-11-01

    Thermal, epithermal and fast neutron fluxes have been measured in a 60 cm long, 'sliced' iron plug, which has been placed in the lower iron lid of the Swedish reactor R1. Au foils, Cu foils, Mn foils, P packets, Cu wires and small Fe cylinders have been used. The gamma flux has been determined with film dosimeters. The measurements have shown that only in the first centimeters of the iron is the activation determined by the thermal flux, which decreases with a relaxation length λ= (1.51 ± 0.02) cm. The epithermal flux is entirely predominant already after 10 cm ( λ = 16 cm). The epithermal neutron flux decreases even more slowly than the fast flux (λ = 6.2 cm)

  8. Isotope - aided studies of the bioavailability of iron and zinc from human diets consumed in Poland

    International Nuclear Information System (INIS)

    Rafalski, H.

    1992-01-01

    The main aims of the study were: 1) the evaluation of iron and zinc status in women of Lodz aged 18-45 years, 2) adaptation of the whole body counter to in vivo measurements absorption of iron given to the gastro-intestinal tract of volunteers and 3) in rat model estimation iron bioavailability from fortified wheat flour combined with products usually consumed in Poland. During five months investigations thirty seven women were examined each one twice in two months interval. Following variables were measured: iron and zinc in blood serum, in public and scalp hair and in food, taste acuity score, serum ferritin, hemoglobin, total iron binding capacity, red blood cells, mean corpuscular concentration and corpuscular volume. Prevalence of iron deficiency and iron deficient anemia were assessed by two models in terms of the depression of serum ferritin and hemoglobin concentrations. 64 refs, 6 figs, 23 tabs

  9. The impact of maternal obesity on iron status, placental transferrin receptor expression and hepcidin expression in human pregnancy.

    Science.gov (United States)

    Garcia-Valdes, L; Campoy, C; Hayes, H; Florido, J; Rusanova, I; Miranda, M T; McArdle, H J

    2015-04-01

    Obesity is associated with decreased iron status, possibly due to a rise in hepcidin, an inflammatory protein known to reduce iron absorption. In animals, we have shown that maternal iron deficiency is minimised in the foetus by increased expression of placental transferrin receptor (pTFR1), resulting in increased iron transfer at the expense of maternal iron stores. This study examines the effect of obesity during pregnancy on maternal and neonatal iron status in human cohorts and whether the placenta can compensate for decreased maternal iron stores by increasing pTFR1 expression. A total of 240 women were included in this study. One hundred and fifty-eight placentas (Normal: 90; Overweight: 37; Obese: 31) were collected at delivery. Maternal iron status was measured by determining serum transferrin receptor (sTFR) and ferritin levels at 24 and 34 weeks and at delivery. Hepcidin in maternal and cord blood was measured by ELISA and pTFR1 in placentas by western blotting and real-time RT-PCR. Low iron stores were more common in obese women. Hepcidin levels (ng ml(-1)) at the end of the pregnancy were higher in obese than normal women (26.03±12.95 vs 18.00±10.77, PMaternal hepcidin levels were correlated with maternal iron status (sTFR r=0.2 P=0.025), but not with neonatal values. mRNA and protein levels of pTFR1 were both inversely related to maternal iron status. For mRNA and all women, sTFR r=0.2 P=0.044. Ferritin mRNA levels correlated only in overweight women r=-0.5 P=0.039 with hepcidin (r=0.1 P=0.349), irrespective of maternal body mass index (BMI). The data support the hypothesis that obese pregnant women have a greater risk of iron deficiency and that hepcidin may be a regulatory factor. Further, we show that the placenta responds to decreased maternal iron status by increasing pTFR1 expression.

  10. Uranium,Radium and Iron Absorption from Liquid Waste Uranium Ore Processing by Zeolite

    International Nuclear Information System (INIS)

    Wismawati, T; Sorot sudiro, A; Herjati, T

    1998-01-01

    The aim of this work is to determine zeolites sorption capacity and the distribution coefficient of uranium, radium, and iron in zeolite-liquid waste system. Mineralogical composition of zeolite used in the experiment has been determine by examining the thin sections of zeolite grains under a microscope. Zeolite has ben activated by the dilute sulfuric acid or sodium hydroxide solution. The results show that the use of 0.25 N sodium hydroxide solution could be optimizing the zeolite for uranium and iron ions sorption and that of 0.1 N sulfuric acid solution is for radium sorption. The re-activation process has been carried out in three hours. Under such a condition, the sorption efficiency of zeolite to those ions have been known to be 45.85% for uranium, 96.63 % for iron and 87.80 % for radium. The distribution coefficients of uranium, radium and iron ion in zeolite-liquid waste system have been calculated 0.85, 7.02, and 28.65 ml/g respectively

  11. Alternating magnetic field energy absorption in the dispersion of iron oxide nanoparticles in a viscous medium

    Czech Academy of Sciences Publication Activity Database

    Smolkova, I.S.; Kazantseva, N.E.; Babayan, V.; Smolka, P.; Parmar, H.; Vilcakova, J.; Schneeweiss, Oldřich; Pizúrová, Naděžda

    2015-01-01

    Roč. 374, JAN (2015), s. 508-515 ISSN 0304-8853 Institutional support: RVO:68081723 Keywords : Iron oxide nanoparticles * Coprecipitation * Magnetic interactions * Specific loss power * Hyperthermia Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.357, year: 2015

  12. Content of zinc, iron, calcium and their absorption inhibitors in foods commonly consumed in Ethiopia

    NARCIS (Netherlands)

    Umeta, M.; West, C.E.; Fufa, H.

    2005-01-01

    The zinc, iron, calcium, phosphorus, phytate, tannin and moisture content of 36 foods consumed in rural Ethiopia were analysed. The foods analysed included those based on cereals, starchy tubers and roots, and legumes and vegetables as well as some fruits. Although many foods were relatively rich in

  13. Extraction of Iron and Manganese from Pyrolusite Absorption Residue by Ammonium Sulphate Roasting–Leaching Process

    Directory of Open Access Journals (Sweden)

    Lin Deng

    2018-01-01

    Full Text Available The residue from desulfurization and denitrification of exhaust gas treatment process with pyrolusite ore as absorbent is regarded as a potential source of iron and manganese. In this study, an extraction process is proposed for recovery of iron and manganese with ammonium sulphate roasting followed by sulphuric acid leaching. Firstly, the conversion mechanism was analyzed through mineral phase analysis of roasting products at different roasting temperature by means of X-ray diffraction (XRD technology. Then, the parameters of the roasting procedure such as roasting temperature and time, ammonium sulphate dosage, leaching temperature, leaching time, and sulphuric acid concentration are examined. The results implicate that the iron oxide and manganese dioxide in the residue are firstly converted into the water-soluble ( NH 4 3 Fe ( SO 4 3 and ( NH 4 2 Mn 2 ( SO 4 3 at 200–350 °C, and then the more stable NH 4 Fe ( SO 4 2 and MnSO 4 are formed, at temperature higher than 350 °C. Under optimum conditions, 95.2% Fe and 97.0% Mn can be extracted. Reactant diffusion through inert layer of silicon dioxide was considered as the rate-limiting step for iron extraction with an activation energy of 20.56 kJ/mol, while, the recovery process of Mn was controlled by both reactant diffusion and chemical reaction with an activation energy of 29.52 kJ/mol.

  14. Facile synthesis of iron oxides/reduced graphene oxide composites: application for electromagnetic wave absorption at high temperature.

    Science.gov (United States)

    Zhang, Lili; Yu, Xinxin; Hu, Hongrui; Li, Yang; Wu, Mingzai; Wang, Zhongzhu; Li, Guang; Sun, Zhaoqi; Chen, Changle

    2015-03-19

    Iron oxides/reduced graphene oxide composites were synthesized by facile thermochemical reactions of graphite oxide and FeSO4 · 7H2O. By adjusting reaction temperature, α-Fe2O3/reduced graphene oxide and Fe3O4/reduced graphene oxide composites can be obtained conveniently. Graphene oxide and reduced graphene oxide sheets were demonstrated to regulate the phase transition from α-Fe2O3 to Fe3O4 via γ-Fe2O3, which was reported for the first time. The hydroxyl groups attached on the graphene oxide sheets and H2 gas generated during the annealing of graphene oxide are believed to play an important role during these phase transformations. These samples showed good electromagnetic wave absorption performance due to their electromagnetic complementary effect. These samples possess much better electromagnetic wave absorption properties than the mixture of separately prepared Fe3O4 with rGO, suggesting the crucial role of synthetic method in determining the product properties. Also, these samples perform much better than commercial absorbers. Most importantly, the great stability of these composites is highly advantageous for applications as electromagnetic wave absorption materials at high temperatures.

  15. Microwave absorption properties of a wave-absorbing coating employing carbonyl-iron powder and carbon black

    International Nuclear Information System (INIS)

    Liu Lidong; Duan Yuping; Ma Lixin; Liu Shunhua; Yu Zhen

    2010-01-01

    To prevent serious electromagnetic interference, a single-layer wave-absorbing coating employing complex absorbents composed of carbonyl-iron powder (CIP) and carbon black (CB) with epoxy resin as matrix was prepared. The morphologies of CIP and CB were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The electromagnetic parameters of CIP and CB were measured in the frequency range of 2-18 GHz by transmission/reflection technology, and the electromagnetic loss mechanisms of the two particles were discussed, respectively. The microwave absorption properties of the coatings were investigated by measuring reflection loss (RL) using arch method. The effects of CIP ratio, CB content and thickness on the microwave absorption properties were discussed, respectively. The results showed that the higher thickness, CIP or CB content could make the absorption band shift towards the lower frequency range. Significantly, the wave-absorbing coating could be applied in different frequency ranges according to actual demand by controlling the content of CIP or CB in composites.

  16. Microwave absorption properties of a wave-absorbing coating employing carbonyl-iron powder and carbon black

    Science.gov (United States)

    Liu, Lidong; Duan, Yuping; Ma, Lixin; Liu, Shunhua; Yu, Zhen

    2010-11-01

    To prevent serious electromagnetic interference, a single-layer wave-absorbing coating employing complex absorbents composed of carbonyl-iron powder (CIP) and carbon black (CB) with epoxy resin as matrix was prepared. The morphologies of CIP and CB were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The electromagnetic parameters of CIP and CB were measured in the frequency range of 2-18 GHz by transmission/reflection technology, and the electromagnetic loss mechanisms of the two particles were discussed, respectively. The microwave absorption properties of the coatings were investigated by measuring reflection loss (RL) using arch method. The effects of CIP ratio, CB content and thickness on the microwave absorption properties were discussed, respectively. The results showed that the higher thickness, CIP or CB content could make the absorption band shift towards the lower frequency range. Significantly, the wave-absorbing coating could be applied in different frequency ranges according to actual demand by controlling the content of CIP or CB in composites.

  17. Human dermal absorption of chlorinated organophosphate flame retardants; implications for human exposure

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Elwafa Abdallah, Mohamed, E-mail: mae_abdallah@yahoo.co.uk [Division of Environmental Health and Risk Management, School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom); Department of Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526 Assiut (Egypt); Pawar, Gopal; Harrad, Stuart [Division of Environmental Health and Risk Management, School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    2016-01-15

    Tris-2-chloroethyl phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCIPP) and tris-1,3-dichloropropyl phosphate (TDCIPP) are organophosphate flame retardants (PFRs) widely applied in a plethora of consumer products despite their carcinogenic potential. Human dermal absorption of these PFRs is investigated for the first time using human ex vivo skin and EPISKIN™ models. Results of human ex vivo skin experiments revealed 28%, 25% and 13% absorption of the applied dose (500 ng/cm{sup 2}, finite dose) of TCEP, TCIPP and TDCIPP, respectively after 24 h exposure. The EPISKIN™ model showed enhanced permeability values (i.e. weaker barrier), that were respectively 16%, 11% and 9% for TCEP, TCIPP and TDCIPP compared to human ex vivo skin. However, this difference was not significant (P > 0.05). Estimated permeability constants (K{sub p}, cm/h) showed a significant negative correlation with log K{sub ow} for the studied contaminants. The effect of hand-washing on dermal absorption of PFRs was investigated. Washing reduced overall dermal absorption, albeit to varying degrees depending on the physicochemical properties of the target PFRs. Moreover, slight variations of the absorbed dose were observed upon changing the dosing solution from acetone to 20% Tween 80 in water, indicating the potential influence of the dose vehicle on the dermal absorption of PFRs. Finally, estimated dermal uptake of the studied PFRs via contact with indoor dust was higher in UK toddlers (median ΣPFRs = 36 ng/kg bw day) than adults (median ΣPFRs = 4 ng/kg bw day). More research is required to fully elucidate the toxicological implications of such exposure. - Highlights: • Human dermal absorption of PFRs was studied using human ex vivo skin and EPISKIN™. • Absorbed fractions of TCEP, TCIPP and TDCIPP were 28%, 25% and 13% of applied dose. • Permeability constants showed significant negative correlation to log K{sub ow} of PFRs. • Skin washing reduced the overall dermal

  18. Human dermal absorption of chlorinated organophosphate flame retardants; implications for human exposure

    International Nuclear Information System (INIS)

    Abou-Elwafa Abdallah, Mohamed; Pawar, Gopal; Harrad, Stuart

    2016-01-01

    Tris-2-chloroethyl phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCIPP) and tris-1,3-dichloropropyl phosphate (TDCIPP) are organophosphate flame retardants (PFRs) widely applied in a plethora of consumer products despite their carcinogenic potential. Human dermal absorption of these PFRs is investigated for the first time using human ex vivo skin and EPISKIN™ models. Results of human ex vivo skin experiments revealed 28%, 25% and 13% absorption of the applied dose (500 ng/cm 2 , finite dose) of TCEP, TCIPP and TDCIPP, respectively after 24 h exposure. The EPISKIN™ model showed enhanced permeability values (i.e. weaker barrier), that were respectively 16%, 11% and 9% for TCEP, TCIPP and TDCIPP compared to human ex vivo skin. However, this difference was not significant (P > 0.05). Estimated permeability constants (K p , cm/h) showed a significant negative correlation with log K ow for the studied contaminants. The effect of hand-washing on dermal absorption of PFRs was investigated. Washing reduced overall dermal absorption, albeit to varying degrees depending on the physicochemical properties of the target PFRs. Moreover, slight variations of the absorbed dose were observed upon changing the dosing solution from acetone to 20% Tween 80 in water, indicating the potential influence of the dose vehicle on the dermal absorption of PFRs. Finally, estimated dermal uptake of the studied PFRs via contact with indoor dust was higher in UK toddlers (median ΣPFRs = 36 ng/kg bw day) than adults (median ΣPFRs = 4 ng/kg bw day). More research is required to fully elucidate the toxicological implications of such exposure. - Highlights: • Human dermal absorption of PFRs was studied using human ex vivo skin and EPISKIN™. • Absorbed fractions of TCEP, TCIPP and TDCIPP were 28%, 25% and 13% of applied dose. • Permeability constants showed significant negative correlation to log K ow of PFRs. • Skin washing reduced the overall dermal absorption of target PFRs

  19. Formation and characterization of iron-binding phosphorylated human-like collagen as a potential iron supplement

    International Nuclear Information System (INIS)

    Deng, Jianjun; Chen, Fei; Fan, Daidi; Zhu, Chenhui; Ma, Xiaoxuan; Xue, Wenjiao

    2013-01-01

    Iron incorporated into food can induce precipitation and unwanted interaction with other components in food. Iron-binding proteins represent a possibility to avoid these problems and other side effects, as the iron is protected. However, there are several technical problems associated with protein–iron complex formation. In this paper, the iron-binding phosphorylated human-like collagen (Fe-G6P-HLC) was prepared under physiological conditions through phosphorylated modification. One molecule of Fe-G6P-HLC possesses about 24 atoms of Fe. Spectroscopy analysis, differential scanning calorimetry (DSC) and equilibrium dialysis techniques were employed to investigate the characteristics of the Fe-G6P-HLC. The binding sites (n b ) and apparent association constant (K app ) between iron and phosphorylated HLC were measured at n b = 23.7 and log K app = 4.57, respectively. The amount of iron (Fe 2+ sulfate) binding to phosphorylated HLC was found to be a function of pH and phosphate content. In addition, the solubility and thermal stability of HLC were not significantly affected. The results should facilitate the utilization of HLC as a bioactive iron supplement in the food and medical industry and provide an important theoretical evidence for the application of HLC chelates. - Highlights: • The iron-binding phosphorylated human-like collagen (Fe-G6P-HLC) was prepared. • One molecule of Fe-G6P-HLC possesses about 24 atoms of Fe. • The binding properties could be modulated through alterations in pH and phosphate content presented in HLC. • A novel strategy for preparing iron-binding proteins was provided

  20. Formation and characterization of iron-binding phosphorylated human-like collagen as a potential iron supplement

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Jianjun; Chen, Fei; Fan, Daidi, E-mail: fandaidi@nwu.edu.cn; Zhu, Chenhui; Ma, Xiaoxuan; Xue, Wenjiao

    2013-10-01

    Iron incorporated into food can induce precipitation and unwanted interaction with other components in food. Iron-binding proteins represent a possibility to avoid these problems and other side effects, as the iron is protected. However, there are several technical problems associated with protein–iron complex formation. In this paper, the iron-binding phosphorylated human-like collagen (Fe-G6P-HLC) was prepared under physiological conditions through phosphorylated modification. One molecule of Fe-G6P-HLC possesses about 24 atoms of Fe. Spectroscopy analysis, differential scanning calorimetry (DSC) and equilibrium dialysis techniques were employed to investigate the characteristics of the Fe-G6P-HLC. The binding sites (n{sub b}) and apparent association constant (K{sub app}) between iron and phosphorylated HLC were measured at n{sub b} = 23.7 and log K{sub app} = 4.57, respectively. The amount of iron (Fe{sup 2+} sulfate) binding to phosphorylated HLC was found to be a function of pH and phosphate content. In addition, the solubility and thermal stability of HLC were not significantly affected. The results should facilitate the utilization of HLC as a bioactive iron supplement in the food and medical industry and provide an important theoretical evidence for the application of HLC chelates. - Highlights: • The iron-binding phosphorylated human-like collagen (Fe-G6P-HLC) was prepared. • One molecule of Fe-G6P-HLC possesses about 24 atoms of Fe. • The binding properties could be modulated through alterations in pH and phosphate content presented in HLC. • A novel strategy for preparing iron-binding proteins was provided.

  1. Extraction and atomic absorption spectrophotometric determination of iron and ruthenium by using potassium xanthates

    Energy Technology Data Exchange (ETDEWEB)

    Aihara, M; Kiboku, M [Kinki Univ., Higashi-Osaka, Osaka (Japan)

    1981-06-01

    Potassium xanthates (potassium o-alkyl dithiocarbonate; KRX) react with many metal ions, and so the complex formation with iron (II, III) ion and the extraction of their complexes has been studied to some extent, but those of ruthenium (III) have not been. Iron-xanthate and ruthenium-xanthate complexes can be extracted into methyl isobutyl ketone (MIBK) from weakly acidic solution to weakly alkaline solution. For quantitative extraction of iron (20 ..mu..g/40 ml), KRX concentration should be above 2.0 x 10/sup -2/ mol dm/sup -3/ of KEtX, 1.0 x 10/sup -2/ mol dm/sup -3/ of KPrX, and 5.0 x 10/sup -3/ mol dm/sup -3/ of KBtX and KPeX, and for that of ruthenium (202 ..mu..g/40 ml), it should be above 2.0 x 10/sup -1/ mol dm/sup -3/ of KEtX and KPrX. Formation constant of ruthenium-xanthate complexes is presumed to be small. A 100-fold excess of Ni(II), Co(II), Cu(II), WO/sub 4//sup 2 -/, PO/sub 4//sup 3 -/, CrO/sub 4//sup 2 -/, and Cr/sub 2/O/sub 7//sup 2 -/ interfered with the determination of iron, however, the interferences are eliminated by adding 5 ml of 0.1 mol dm/sup -3/ ascorbic acid solution. For the determination of ruthenium, a 50-fold excess of Ag(I), Hg(II), Pb(II), Zn(II), Mn(II), Cr(III), and Pt(II), or a 100-fold excess of NO/sub 2//sup -/, S/sub 2/O/sub 3//sup 2 -/, CrO/sub 4//sup 2 -/ and Cr/sub 2/O/sub 7//sup 2 -/, respectively, interfered. The coefficient of variation after each ten runs, ranges from 0.9% to 3.2% in the determination of 10 ..mu..g, 20 ..mu..g, and 30 ..mu..g of iron, and from 1.4% to 4.3% in the determination of 100 ..mu..g, 200 ..mu..g, and 300 ..mu..g of ruthenium. The determination limit in aqueous samples is 0.02 ppm for iron and 0.2 ppm for ruthenium, when the volume ratio of aqueous phase to organic phase (MIBK) is 10:1.

  2. Formation and characterization of iron-binding phosphorylated human-like collagen as a potential iron supplement.

    Science.gov (United States)

    Deng, Jianjun; Chen, Fei; Fan, Daidi; Zhu, Chenhui; Ma, Xiaoxuan; Xue, Wenjiao

    2013-10-01

    Iron incorporated into food can induce precipitation and unwanted interaction with other components in food. Iron-binding proteins represent a possibility to avoid these problems and other side effects, as the iron is protected. However, there are several technical problems associated with protein-iron complex formation. In this paper, the iron-binding phosphorylated human-like collagen (Fe-G6P-HLC) was prepared under physiological conditions through phosphorylated modification. One molecule of Fe-G6P-HLC possesses about 24 atoms of Fe. Spectroscopy analysis, differential scanning calorimetry (DSC) and equilibrium dialysis techniques were employed to investigate the characteristics of the Fe-G6P-HLC. The binding sites (nb) and apparent association constant (Kapp) between iron and phosphorylated HLC were measured at nb=23.7 and log Kapp=4.57, respectively. The amount of iron (Fe(2+) sulfate) binding to phosphorylated HLC was found to be a function of pH and phosphate content. In addition, the solubility and thermal stability of HLC were not significantly affected. The results should facilitate the utilization of HLC as a bioactive iron supplement in the food and medical industry and provide an important theoretical evidence for the application of HLC chelates. © 2013.

  3. Iron K Features in the Quasar E 1821+643: Evidence for Gravitationally Redshifted Absorption?

    Science.gov (United States)

    Yaqoob, Tahir; Serlemitsos, Peter

    2005-01-01

    We report a Chandra high-energy grating detection of a narrow, redshifted absorption line superimposed on the red wing of a broad Fe K line in the z = 0.297 quasar E 1821+643. The absorption line is detected at a confidence level, estimated by two different methods, in the range approx. 2 - 3 sigma. Although the detection significance is not high enough to exclude a non-astrophysical origin, accounting for the absorption feature when modeling the X-ray spectrum implies that the Fe-K emission line is broad, and consistent with an origin in a relativistic accretion disk. Ignoring the apparent absorption feature leads to the conclusion that the Fe-K emission line is narrower, and also affects the inferred peak energy of the line (and hence the inferred ionization state of Fe). If the absorption line (at approx. 6.2 keV in the quasar frame) is real, we argue that it could be due to gravitationally redshifted Fe XXV or Fe XXVI resonance absorption within approx. 10 - 20 gravitational radii of the putative central black hole. The absorption line is not detected in earlier ASCA and Chandra low-energy grating observations, but the absorption line is not unequivocally ruled out by these data. The Chandra high-energy grating Fe-K emission line is consistent with an origin predominantly in Fe I-XVII or so. In an ASCA observation eight years earlier, the Fe-K line peaked at approx. 6.6 keV, closer to the energies of He-like Fe triplet lines. Further, in a Chandra low-energy grating observation the Fe-K line profile was double-peaked, one peak corresponding to Fe I-XVII or so, the other peak to Fe XXVI Ly alpha. Such a wide range in ionization state of Fe is not ruled out by the HEG and ASCA data either, and is suggestive of a complex structure for the line-emitter.

  4. Mechanism of Dimercaptosuccinic Acid Coated Superparamagnetic Iron Oxide Nanoparticles with Human Serum Albumin.

    Science.gov (United States)

    Zhao, Lining; Song, Wei; Wang, Jing; Yan, Yunxing; Chen, Jiangwei; Liu, Rutao

    2015-12-01

    To research the mechanism of dimercaptosuccinic acid coated-superparamagnetic iron oxide nanoparticles (SPION) with human serum albumin (HSA), the methods of spectroscopy, molecular modeling calculation, and calorimetry were used in this paper. The inner filter effect of the fluorescence intensity was corrected to obtain the accurate results. Ultraviolet-visible absorption and circular dichroism spectra reflect that SPION changed the secondary structure with a loss of α-helix and loosened the protein skeleton of HSA; the activity of the protein was also affected by the increasing exposure of SPION. Fluorescence lifetime measurement indicates that the quenching mechanism type of this system was static quenching. The isothermal titration calorimetry measurement and molecular docking calculations prove that the predominant force of this system was the combination of Van der Waals' force and hydrogen bonds. © 2015 Wiley Periodicals, Inc.

  5. Isotope aided studies of the bioavailability of iron from human diets consumed in Peru

    International Nuclear Information System (INIS)

    Zavaleta, N.; Penny, M.; Berlanga, R.; Diaz, A.; Montoya, E.; Lonnerdal, B.

    1994-01-01

    Iron deficiency anaemia is an important health problem in Peru, which affects approximately 25% of the population. The most vulnerable groups are children below 5 years of age and pregnant women, of whom 64% and 53% respectively are anemic. The main reason for this deficiency is inadequate iron intake. Heme iron consumption is very low, and non-heme iron is virtually the only source of iron in the diet. Despite regional differences in food consumption, wheat, salt and sugar are widely consumed in all areas. Wheat is likely to be the most suitable food vehicle for iron fortification due to the processing required. Based on the recent food consumption surveys conducted in Lima by the IIN, we selected examples of typical main meals and measured iron bioavailability in the diet using an extrinsic tag method with 1.5 μCi of 59 Fe and 5 μCi of 55 Fe as markers. Coffee with bread and butter for breakfast, noodle soup with vegetables, rice with seasoned tripe (cow), bread and lemonade for lunch; and noodle soup with vegetables and bread for dinner were used to measure iron absorption. Thirteen adults in apparent good health, 5 male and 8 female, with normal hemoglobin levels participated in the study. The mean iron absorption from breakfast was 4.2% ± 4.1; from lunch 14.65% ± 10/95, and from dinner 5.1% ± 2.84. The presence of heme iron from tripe and ascorbic acid from lemonade improved iron absorption. (author). 17 refs, 3 tabs

  6. Labeling Efficacy of Superparamagnetic Iron Oxide Nanoparticles to Human Neural Stem Cells: Comparison of Ferumoxides, Monocrystalline Iron Oxide, Cross-linked Iron Oxide (CLIO)-NH2 and tat-CLIO

    International Nuclear Information System (INIS)

    Song, Mi Yeoun; Moon, Woo Kyung; Kim, Yun Hee; Song, In Chan; Yoon, Byung Woo; Lim, Dong Yeol

    2007-01-01

    We wanted to compare the human neural stem cell (hNSC) labeling efficacy of different superparamagnetic iron oxide nanoparticles (SPIONs), namely, ferumoxides, monocrystalline iron oxide (MION), cross-linked iron oxide (CLIO)-NH 2 and tat-CLIO. The hNSCs (5x10 5 HB1F3 cells/ml) were incubated for 24 hr in cell culture media that contained 25 μg/ml of ferumoxides, MION or CLIO-NH 2 , and with or without poly-L-lysine (PLL) and tat-CLIO. The cellular iron uptake was analyzed qualitatively with using a light microscope and this was quantified via atomic absorption spectrophotometry. The visibility of the labeled cells was assessed with MR imaging. The incorporation of SPIONs into the hNSCs did not affect the cellular proliferations and viabilities. The hNSCs labeled with tat-CLIO showed the longest retention, up to 72 hr, and they contained 2.15± 0.3 pg iron/cell, which are 59 fold, 430 fold and six fold more incorporated iron than that of the hNSCs labeled with ferumoxides, MION or CLIO-NH 2 , respectively. However, when PLL was added, the incorporation of ferumoxides, MION or CLIO-NH 2 into the hNSCs was comparable to that of tat-CLIO. For MR imaging, hNSCs can be efficiently labeled with tat-CLIO alone or with a combination of ferumoxides, MION, CLIO-NH 2 and the transfection agent PLL

  7. Labeling Efficacy of Superparamagnetic Iron Oxide Nanoparticles to Human Neural Stem Cells: Comparison of Ferumoxides, Monocrystalline Iron Oxide, Cross-linked Iron Oxide (CLIO)-NH2 and tat-CLIO

    Science.gov (United States)

    Song, Miyeoun; Kim, Yunhee; Lim, Dongyeol; Song, In-Chan; Yoon, Byung-Woo

    2007-01-01

    Objective We wanted to compare the human neural stem cell (hNSC) labeling efficacy of different superparamagnetic iron oxide nanoparticles (SPIONs), namely, ferumoxides, monocrystalline iron oxide (MION), cross-linked iron oxide (CLIO)-NH2 and tat-CLIO. Materials and Methods The hNSCs (5 × 105 HB1F3 cells/ml) were incubated for 24 hr in cell culture media that contained 25 µg/ml of ferumoxides, MION or CLIO-NH2, and with or without poly-L-lysine (PLL) and tat-CLIO. The cellular iron uptake was analyzed qualitatively with using a light microscope and this was quantified via atomic absorption spectrophotometry. The visibility of the labeled cells was assessed with MR imaging. Results The incorporation of SPIONs into the hNSCs did not affect the cellular proliferations and viabilities. The hNSCs labeled with tat-CLIO showed the longest retention, up to 72 hr, and they contained 2.15 ± 0.3 pg iron/cell, which are 59 fold, 430 fold and six fold more incorporated iron than that of the hNSCs labeled with ferumoxides, MION or CLIO-NH2, respectively. However, when PLL was added, the incorporation of ferumoxides, MION or CLIO-NH2 into the hNSCs was comparable to that of tat-CLIO. Conclusion For MR imaging, hNSCs can be efficiently labeled with tat-CLIO alone or with a combination of ferumoxides, MION, CLIO-NH2 and the transfection agent PLL. PMID:17923778

  8. Sugars increase non-heme iron bioavailability in human epithelial intestinal and liver cells.

    Directory of Open Access Journals (Sweden)

    Tatiana Christides

    Full Text Available Previous studies have suggested that sugars enhance iron bioavailability, possibly through either chelation or altering the oxidation state of the metal, however, results have been inconclusive. Sugar intake in the last 20 years has increased dramatically, and iron status disorders are significant public health problems worldwide; therefore understanding the nutritional implications of iron-sugar interactions is particularly relevant. In this study we measured the effects of sugars on non-heme iron bioavailability in human intestinal Caco-2 cells and HepG2 hepatoma cells using ferritin formation as a surrogate marker for iron uptake. The effect of sugars on iron oxidation state was examined by measuring ferrous iron formation in different sugar-iron solutions with a ferrozine-based assay. Fructose significantly increased iron-induced ferritin formation in both Caco-2 and HepG2 cells. In addition, high-fructose corn syrup (HFCS-55 increased Caco-2 cell iron-induced ferritin; these effects were negated by the addition of either tannic acid or phytic acid. Fructose combined with FeCl3 increased ferrozine-chelatable ferrous iron levels by approximately 300%. In conclusion, fructose increases iron bioavailability in human intestinal Caco-2 and HepG2 cells. Given the large amount of simple and rapidly digestible sugars in the modern diet their effects on iron bioavailability may have important patho-physiological consequences. Further studies are warranted to characterize these interactions.

  9. Isotope aided studies of the bioavailability of iron and zinc from human diets consumed in Venezuela

    International Nuclear Information System (INIS)

    Layrisse, M.A.

    1994-01-01

    Previous studies on Venezuelan diets provided information on food consumed in each diet and their nutritional contents. It also showed the comparison of the iron absorption from these diets when given in the morning after over-night fast and when given at the customary time of the day. It was observed that the iron absorption from the lunch given at noon was slightly higher (although not significant) in Zulia and Sucre diets. There were no significant differences between the Zulia lunch given in the morning after over-night fast at noon. Similar results were observed in the Sucre diet lunch repeated twice. From these results we can state that iron absorption from meals is not affected by the time it is administered with the condition that the subjects tested have had a previous fast of three hours before the meal is administered. The significant difference in iron absorption in the first study could be due to a marked physiological daily variation in iron absorption. The results from these studies provide credit to previous reports in which meals were given in the morning after an over-night fast. The iron absorption studies from 11 diets consumed by the Venezuelan population, provided the basic information for the establishment of a programme on iron fortification. The Government of Venezuela, according to the recommendation of the National Nutrition Institute, approved a national programme of iron fortification by enriching precooked maize flour with ferrous fumarate in the proportion of 5 mg Fe/100 g flour, and the enrichment of flour used to produce paste with the same iron compound in the proportion of 3 mg Fe/100 g flour. This year, the Chemical Centre of the Venezuela Scientific Institute of Research discovered an iron compound, now called FERROIVIC. It is an insoluble white powder that, when given as iron fortification, forms part of the nonhaeme iron pool and it is absorbed to the same extent as ferrous sulphate; it is stable for several months. 15 refs, 8

  10. Kinetics of iron redox reactions in silicate liquids: A high-temperature X-ray absorption and Raman spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Magnien, V. [Physique des Mineraux et Magmas, CNRS-IPGP, 4 place Jussieu, 75252 Paris cedex 05 (France); CEA VALRHO Marcoule, SCDV, LEBV, BP 17171, 30207 Bagnols/Ceze (France); Neuville, D.R. [Physique des Mineraux et Magmas, CNRS-IPGP, 4 place Jussieu, 75252 Paris cedex 05 (France)]. E-mail: neuville@ipgp.jussieu.fr; Cormier, L. [IMPMC, CNRS UMR 7590, Universites Paris 6 and 7 and IPGP, 4 place Jussieu, 75252 Paris cedex 05 (France); Roux, J. [Physique des Mineraux et Magmas, CNRS-IPGP, 4 place Jussieu, 75252 Paris cedex 05 (France); Hazemann, J.-L. [Laboratoire de cristallographie, UPR 5031, CNRS, 38043 Grenoble (France); Pinet, O. [CEA VALRHO Marcoule, SCDV, LEBV, BP 17171, 30207 Bagnols/Ceze (France); Richet, P. [Physique des Mineraux et Magmas, CNRS-IPGP, 4 place Jussieu, 75252 Paris cedex 05 (France)

    2006-06-30

    The oxidation kinetics of a Fe-bearing supercooled liquid of the system SiO{sub 2}-CaO-MgO-Na{sub 2}O-FeO has been determined near the glass transition range by X-ray absorption near edge structure (XANES) and Raman spectroscopies. Both techniques yield room-temperature iron redox ratios in accord with wet chemical, Moessbauer and electron microprobe analyses. Similar oxidation kinetics have also been observed with both methods. At constant temperature, the kinetics obey an exponential law with a characteristic time that follows an Arrhenian temperature dependence. As redox changes are too fast to be accounted for in terms of diffusion of either ionic or molecular oxygen, these results lend further support to the idea that the rate-limiting factor for oxidation near the glass transition is diffusion of network-modifying cations along with a flux of electron holes.

  11. Iron in diet

    Science.gov (United States)

    ... Reasonable amounts of iron are also found in lamb, pork, and shellfish. Iron from vegetables, fruits, grains, ... strawberries, tomatoes, and potatoes) also increase iron absorption. Cooking foods in a cast-iron skillet can also ...

  12. Temperature dependence of the electromagnetic properties and microwave absorption of carbonyl iron particles/silicone resin composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yingying; Zhou, Wancheng; Qing, Yuchang; Luo, Fa; Zhu, Dongmei

    2015-01-15

    Microwave absorbing composites with thin thickness and wideband absorption were successfully prepared by a spraying method using carbonyl iron particles (CIPs) as absorbers and silicone resin as the matrix. The value of reflection loss (RL) below −5 dB can be obtained in the frequency range of 5.76–18 GHz for the composite with 0.8 mm thickness. The temperature dependence of electromagnetic properties and RL of the composites were investigated. The RL of the composite showed a slight variation when the temperature reached up to 200 °C while decreased at 300 °C. The room temperature RL of the composite did not display significant difference before and after the heat treatment at 300 °C for 10 h; the mechanism was also discussed. - Highlights: • Carbonyl iron particles/silicone resin composites are prepared by a spraying method. • Reflection loss values exceed −5 dB at 5.76–18 GHz for an absorber of 0.8 mm thickness. • The variation of reflection loss was studied from room temperature to 300 °C.

  13. Absorption of Nickel, Chromium, and Iron by the Root Surface of Primary Molars Covered with Stainless Steel Crowns

    Directory of Open Access Journals (Sweden)

    David Keinan

    2010-01-01

    Full Text Available Objective. The purpose of this study was to analyze the absorption of metal ions released from stainless steel crowns by root surface of primary molars. Study Design. Laboratory research: The study included 34 primary molars, exfoliated or extracted during routine dental treatment. 17 molars were covered with stainless-steel crowns for more than two years and compared to 17 intact primary molars. Chemical content of the mesial or distal root surface, 1 mm apically to the crown or the cemento-enamel junction (CEJ, was analyzed. An energy dispersive X-ray spectrometer (EDS was used for chemical analysis. Results. Higher amounts of nickel, chromium, and iron (5-6 times were found in the cementum of molars covered with stainless-steel crowns compared to intact molars. The differences between groups were highly significant (<.001. Significance. Stainless-steel crowns release nickel, chromium, and iron in oral environment, and the ions are absorbed by the primary molars roots. The additional burden of allergenic metals should be reduced if possible.

  14. Oxygen, Neon, and Iron X-Ray Absorption in the Local Interstellar Medium

    Science.gov (United States)

    Gatuzz, Efrain; Garcia, Javier; Kallman, Timothy R.; Mendoza, Claudio

    2016-01-01

    We present a detailed study of X-ray absorption in the local interstellar medium by analyzing the X-ray spectra of 24 galactic sources obtained with the Chandra High Energy Transmission Grating Spectrometer and the XMM-Newton Reflection Grating Spectrometer. Methods. By modeling the continuum with a simple broken power-law and by implementing the new ISMabs X-ray absorption model, we have estimated the total H, O, Ne, and Fe column densities towards the observed sources. Results. We have determined the absorbing material distribution as a function of source distance and galactic latitude longitude. Conclusions. Direct estimates of the fractions of neutrally, singly, and doubly ionized species of O, Ne, and Fe reveal the dominance of the cold component, thus indicating an overall low degree of ionization. Our results are expected to be sensitive to the model used to describe the continuum in all sources.

  15. Time dependent density functional theory of light absorption in dense plasmas: application to iron-plasma

    International Nuclear Information System (INIS)

    Grimaldi, F.; Grimaldi-Lecourt, A.; Dharma-Wardana, M.W.C.

    1986-10-01

    The objective of this paper is to present a simple time-dependent calculation of the light absorption cross section for a strongly coupled partially degenerate plasma so as to transcend the usual single-particle picture. This is achieved within the density functional theory (DFT) of plasmas by generalizing the method given by Zangwill and Soven for atomic calculations at zero temperature. The essential feature of the time dependent DFT is the correct treatment of the relaxation of the system under the external field. Exploratory calculations for a Fe-plasma at 100 eV show new features in the absorption cross section which are absent in the usual single particle theory. These arise from inter-shell correlations, channel mixing and self-energy effects. These many-body effects introduce significant modifications to the radiative properties of plasmas and are shown to be efficiently calculable by time dependent density functional theory (TD-DFT)

  16. Time dependent density functional theory of light absorption in dense plasmas: application to iron-plasma

    International Nuclear Information System (INIS)

    Grimaldi, F.; Grimaldi-Lecourt, A.; Dharma-Wardana, M.W.C.

    1985-02-01

    The objective of this paper is to present a simple time-dependent calculation of the light absorption cross section for a strongly coupled partially degenerate plasma so as to transcend the usual single-particle picture. This is achieved within the density functional theory (DFT) of plasmas by generalizing the method given by Zangwill and Soven for atomic calculations at zero temperature. The essential feature of the time dependent DFT is the correct treatment of the relaxation of the system under the external field. Exploratory calculations for an Fe-plasma at 100 eV show new features in the absorption cross section which are absent in the usual single particle theory. These arise from inter-shell correlations, channel mixing and self-energy effects. These many-body effects introduce significant modifications to the radiative properties of plasma and are shown to be efficiently calculable by time dependent density functional theory (TD-DFT)

  17. Stimulation of butyrate absorption in the human rectum in vivo

    DEFF Research Database (Denmark)

    Holtug, K; Hove, H; Mortensen, P B

    1995-01-01

    BACKGROUND: Models of short-chain fatty acid absorption have focused on the stimulation of sodium absorption, an effect mainly located in the proximal colon of man. With the present efforts to utilize butyrate enemas as a treatment of ulcerative colitis, it seemed important to assess the transport...... in the rectum. METHODS: Non-equilibrium dialysis of the rectum was applied by placing dialysis bags containing various electrolyte solutions in the rectum of volunteers for 30 min. In this period changes in ion concentrations were linear with time. Net absorption and secretion rates were calculated from...

  18. Iron homeostasis during pregnancy.

    Science.gov (United States)

    Fisher, Allison L; Nemeth, Elizabeta

    2017-12-01

    During pregnancy, iron needs to increase substantially to support fetoplacental development and maternal adaptation to pregnancy. To meet these iron requirements, both dietary iron absorption and the mobilization of iron from stores increase, a mechanism that is in large part dependent on the iron-regulatory hormone hepcidin. In healthy human pregnancies, maternal hepcidin concentrations are suppressed in the second and third trimesters, thereby facilitating an increased supply of iron into the circulation. The mechanism of maternal hepcidin suppression in pregnancy is unknown, but hepcidin regulation by the known stimuli (i.e., iron, erythropoietic activity, and inflammation) appears to be preserved during pregnancy. Inappropriately increased maternal hepcidin during pregnancy can compromise the iron availability for placental transfer and impair the efficacy of iron supplementation. The role of fetal hepcidin in the regulation of placental iron transfer still remains to be characterized. This review summarizes the current understanding and addresses the gaps in knowledge about gestational changes in hematologic and iron variables and regulatory aspects of maternal, fetal, and placental iron homeostasis. © 2017 American Society for Nutrition.

  19. Iron

    DEFF Research Database (Denmark)

    Hansen, Jakob Bondo; Moen, I W; Mandrup-Poulsen, T

    2014-01-01

    and discuss recent evidence, suggesting that iron is a key pathogenic factor in both type 1 and type 2 diabetes with a focus on inflammatory pathways. Pro-inflammatory cytokine-induced β-cell death is not fully understood, but may include iron-induced ROS formation resulting in dedifferentiation by activation...... of transcription factors, activation of the mitochondrial apoptotic machinery or of other cell death mechanisms. The pro-inflammatory cytokine IL-1β facilitates divalent metal transporter 1 (DMT1)-induced β-cell iron uptake and consequently ROS formation and apoptosis, and we propose that this mechanism provides...

  20. Visualization of antigen-specific human cytotoxic T lymphocytes labeled with superparamagnetic iron-oxide particles

    Energy Technology Data Exchange (ETDEWEB)

    Beer, Ambros J. [Technical University of Munich (TUM), Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Holzapfel, Konstantin; Settles, Marcus; Rummeny, Ernst J. [Technical University of Munich, Department of Radiology, Klinikum rechts der Isar, Munich (Germany); Neudorfer, Juliana; Kroenig, Holger; Peschel, Christian; Bernhard, Helga [TUM, Munich, Department of Hematology/Oncology, Klinikum rechts der Isar, Munich (Germany); Piontek, Guido; Schlegel, Juergen [TUM, Munich, Division of Neuropathology, Institute of Pathology, Klinikum rechts der Isar, Munich (Germany)

    2008-06-15

    New technologies are needed to characterize the migration and survival of antigen-specific T cells in vivo. In this study, we developed a novel technique for the labeling of human cytotoxic T lymphocytes with superparamagnetic iron-oxide particles and the subsequent depiction with a conventional 1.5-T magnetic resonance scanner. Antigen-specific CD8{sup +} T lymphocytes were labeled with ferucarbotran by lipofection. The uptake of ferucarbotran was confirmed by immunofluorescence microscopy using a dextran-specific antibody, and the intracellular enrichment of iron was measured by atomic absorption spectrometry. The imaging of T cells was performed by magnetic resonance on day 0, 2, 7 and 14 after the labeling procedure. On day 0 and 2 post labeling, a pronounced shortening of T2*-relaxation times was observed, which diminished after 7 days and was not detectable anymore after 14 days, probably due to the retained mitotic activity of the labeled T cells. Of importance, the antigen-specific cytolytic activity of the T cells was preserved following ferucarbotran labeling. Efficient ferucarbotran labeling of functionally active T lymphocytes and their detection by magnetic resonance imaging allows the in vivo monitoring of T cells and, subsequently, will impact the further development of T cell-based therapies. (orig.)

  1. Visualization of antigen-specific human cytotoxic T lymphocytes labeled with superparamagnetic iron-oxide particles

    International Nuclear Information System (INIS)

    Beer, Ambros J.; Holzapfel, Konstantin; Settles, Marcus; Rummeny, Ernst J.; Neudorfer, Juliana; Kroenig, Holger; Peschel, Christian; Bernhard, Helga; Piontek, Guido; Schlegel, Juergen

    2008-01-01

    New technologies are needed to characterize the migration and survival of antigen-specific T cells in vivo. In this study, we developed a novel technique for the labeling of human cytotoxic T lymphocytes with superparamagnetic iron-oxide particles and the subsequent depiction with a conventional 1.5-T magnetic resonance scanner. Antigen-specific CD8 + T lymphocytes were labeled with ferucarbotran by lipofection. The uptake of ferucarbotran was confirmed by immunofluorescence microscopy using a dextran-specific antibody, and the intracellular enrichment of iron was measured by atomic absorption spectrometry. The imaging of T cells was performed by magnetic resonance on day 0, 2, 7 and 14 after the labeling procedure. On day 0 and 2 post labeling, a pronounced shortening of T2*-relaxation times was observed, which diminished after 7 days and was not detectable anymore after 14 days, probably due to the retained mitotic activity of the labeled T cells. Of importance, the antigen-specific cytolytic activity of the T cells was preserved following ferucarbotran labeling. Efficient ferucarbotran labeling of functionally active T lymphocytes and their detection by magnetic resonance imaging allows the in vivo monitoring of T cells and, subsequently, will impact the further development of T cell-based therapies. (orig.)

  2. X-ray absorption spectroscopy of soybean lipoxygenase-1 : Influence of lipid hydroperoxide activation and lyophilization on the structure of the non-heme iron active site

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Heijdt, L.M. van der; Feiters, M.C.; Navaratnam, S.; Nolting, H.-F.; Hermes, C.; Veldink, G.A.

    1992-01-01

    X-ray absorption spectra at the Fe K-edge of the non-heme iron site in Fe(II) as well as Fe(III) soybean lipoxygenase-1, in frozen solution or lyophilized, are presented; the latter spectra were obtained by incubation of the Fe(II) enzyme with its product hydroperoxide. An edge shift of about 23 eV

  3. Electronic Structure from Iron L-edge Spectroscopy : An Example of Spin Transition Evidenced by Soft X-ray Absorption Spectroscopy

    NARCIS (Netherlands)

    Cartier dit Moulin, Ch.; Flank, A.M.; Rudolf, P.; Chen, C.T.

    1993-01-01

    Soft X-ray Absorption Spectroscopy at the transition metal L2,3 edges provides information about the 3d unoccupied states by dipole allowed transitions. We have recorded iron L2,3 edges in order to follow the reversible thermal spin interconversion (S=2 S=0) of the Fe(II)(o-phenantroline)2(NCS)2.

  4. Iron

    Science.gov (United States)

    ... Share: Search the ODS website Submit Search NIH Office of Dietary Supplements Consumer Datos en español Health ... eating a variety of foods, including the following: Lean meat, seafood, and poultry. Iron-fortified breakfast cereals ...

  5. Absorption and translocation of 59Fe and 14C-rhodotorulate in iron-stressed tomato

    International Nuclear Information System (INIS)

    Miller, G.W.; Shigematsu, A.; Motoji, N.; Shibabe, S.

    1990-01-01

    Tomato plants, cultivars FER and Earlygirl (both iron efficient and able to use rhodotorulate- 59 Fe), were grown under low Fe conditions for 9 days. Rhodotorulate- 14 C, isolated from Rhodotorula pilimanae cultured with 14 C-sucrose, and rhodotorulate- 59 Fe were added to the Fe-stressed plants for 6-, 24- or 48-h periods. It was evident from autoradiograms and tissue sampling that 59 Fe and 14 C were abundant in roots, stems and leaves. The 14 C autoradiograms showed especially high density in the small, younger leaves, as was found also with 59 Fe. Unlike synthetic chelates, rhodotorulate (or metabolised derivatives) was readily absorbed by the roots and translocated to the leaves. (author)

  6. Alcohol-catalyzed photoreduction of iron-porphyrin complexes revealed by resonance raman and absorption spectroscopies

    Science.gov (United States)

    Ogura, T.; Fidler, V.; Ozaki, Y.; Kitagawa, T.

    1990-06-01

    Photoreduction of Fe III(OEP) (2-MeIm) (OEP is octaethylporphyrin; 2-MeIm is 2-methylimidazole) was found to be catalyzed by a trace amount of MeOH present in Ch 2Cl 2 as a stabilizer. The absence of either 2-MeIm or MeOH in the CH 2Cl 2 solution of Fe III(OEP) X (X is Cl -, Br - or I -) leads to no photoreduction. The presence of MeOH in the Fe III(OEP) (2-MeIm) solution results in the appearance of a new absorption band at 585 nm, and when Raman scattering was excited at 590 nm, a new Raman band appeared at 524 cm -. This band exhibited an upshift by 4 cm - with 54Fe(OEP) (2-MeIm)(CH 3OH) and a downshift by 12 cm -1 with 56Fe(OEP)(2-MeIm) (CD 3OD) and was therefore assigned to the Fe III-MeOH stretching vibration. The excitation profile of this band gave a peak around 585 nm and accordingly, the new absorption band at 584 nm was assigned to a charge-transfer (CT) band from MeOH to the Fe III ion. It was most unexpected that the photoreduction did not occur upon laser illumination within the CT band.

  7. Observation of auto-oscillations and chaos in subsidiary absorption in yttrium iron garnet

    International Nuclear Information System (INIS)

    Srinivasan, G.; Chen, M.; Patton, C.E.

    1988-01-01

    Auto-oscillations of the dynamic magnetization and routes to chaos for the first-order transverse pump spin-wave instability have been studied in single-crystal yttrium-iron-garnet (YIG) films. The measurements reported here were made on a 20.8-μm-thick YIG film at 9.4 GHz with the static and microwave fields in the plane of the film. Auto-oscillations at 100--400 kHz were observed in the power absorbed by the film over a relatively narrow static field range of 1100--1460 Oe, compared to the first-order instability (FOI) range of 0--1630 Oe. The auto-oscillation frequency and threshold microwave field amplitude were both strongly field dependent. The threshold amplitudes were about a factor of 2 larger than the FOI threshold amplitudes. At even higher power levels and for an even narrower field range of 1300--1380 Oe, the auto-oscillations showed frequency changes indicative of chaotic behavior. Several different subharmonic bifurcation routes to chaos were observed for different fields within the chaotic region

  8. Insights into Digestion and Absorption of Major Nutrients in Humans

    Science.gov (United States)

    Goodman, Barbara E.

    2010-01-01

    Nutrient digestion and absorption is necessary for the survival of living organisms and has evolved into the complex and specific task of the gastrointestinal (GI) system. While most people simply assume that their GI tract will work properly to use nutrients, provide energy, and release wastes, few nonscientists know the details about how various…

  9. Absorption of beta-carotene and other carotenoids in humans and animal models : a review

    NARCIS (Netherlands)

    Vliet, T. van

    1996-01-01

    Objective: To review available information on absorption and further metabolism of different carotenoids in man and to discuss animal models and approaches in the study of carotenoid absorption and metabolism in man. Conclusions: Humans appear to absorb various carotenoids in a relatively

  10. The effect of exercise on the absorption of inhaled human insulin in healthy volunteers

    DEFF Research Database (Denmark)

    Petersen, Astrid Heide; Kohler, Gerd; Korsatko, Stefan

    2008-01-01

    overall absorption. Aims To investigate the effect of moderate exercise on the absorption of inhaled insulin. Methods A single-centre, randomized, open-label, three-period cross-over trial was carried out in 12 nonsmoking healthy subjects. A dose of 3.5 mg inhaled human insulin was administered via...

  11. ABSORPTION-SPECTRA OF HUMAN FETAL AND ADULT OXYHEMOGLOBIN, DE-OXYHEMOGLOBIN, CARBOXYHEMOGLOBIN, AND METHEMOGLOBIN

    NARCIS (Netherlands)

    ZIJLSTRA, WG; MEEUWSENVANDERROEST, WP

    We determined the millimolar absorptivities of the four clinically relevant derivatives of fetal and adult human hemoglobin in the visible and near-infrared spectral range (450-1000 nm). As expected, spectral absorption curves of similar shape were found, but the small differences between fetal and

  12. Monte Carlo simulations of the detailed iron absorption line profiles from thermal winds in X-ray binaries

    Science.gov (United States)

    Tomaru, Ryota; Done, Chris; Odaka, Hirokazu; Watanabe, Shin; Takahashi, Tadayuki

    2018-05-01

    Blueshifted absorption lines from highly ionized iron are seen in some high inclination X-ray binary systems, indicating the presence of an equatorial disc wind. This launch mechanism is under debate, but thermal driving should be ubiquitous. X-ray irradiation from the central source heats disc surface, forming a wind from the outer disc where the local escape velocity is lower than the sound speed. The mass-loss rate from each part of the disc is determined by the luminosity and spectral shape of the central source. We use these together with an assumed density and velocity structure of the wind to predict the column density and ionization state, then combine this with a Monte Carlo radiation transfer to predict the detailed shape of the absorption (and emission) line profiles. We test this on the persistent wind seen in the bright neutron star binary GX 13+1, with luminosity L/LEdd ˜ 0.5. We approximately include the effect of radiation pressure because of high luminosity, and compute line features. We compare these to the highest resolution data, the Chandra third-order grating spectra, which we show here for the first time. This is the first physical model for the wind in this system, and it succeeds in reproducing many of the features seen in the data, showing that the wind in GX13+1 is most likely a thermal-radiation driven wind. This approach, combined with better streamline structures derived from full radiation hydrodynamic simulations, will allow future calorimeter data to explore the detail wind structure.

  13. Speciation of water soluble iron in size segregated airborne particulate matter using LED based liquid waveguide with a novel dispersive absorption spectroscopic measurement technique

    International Nuclear Information System (INIS)

    Chan, K.L.; Jiang, S.Y.N.; Ning, Z.

    2016-01-01

    In this study, we present the development and evaluation of a dispersive absorption spectroscopic technique for trace level soluble ferrous detection. The technique makes use of the broadband absorption spectra of the ferrous-ferrozine complex with a novel spectral fitting algorithm to determine soluble ferrous concentrations in samples and achieves much improved measurement precision compared to conventional methods. The developed method was evaluated by both model simulations and experimental investigations. The results demonstrated the robustness of the method against the spectral fluctuation, wavelength drift and electronic noise, while achieving excellent linearity (R 2  > 0.999) and low detection limit (0.06 μg L −1 ) for soluble ferrous detection. The developed method was also used for the speciation of soluble iron in size segregated atmospheric aerosols. The measurement was carried out during Spring and Summer in typical urban environment in Hong Kong. The measured total iron concentrations are in good agreement compared to conventional Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES) measurements. Investigation on ambient particulate matter samples shows the size dependent characteristic of iron speciation in the atmosphere with a more active role of fine particles in transforming between ferrous and ferric. The method demonstrated in this study provides a cost and time effective approach for the speciation of iron in ambient aerosols. - Highlights: • Dispersive absorption spectroscopic technique for trace level ferrous detection. • The spectral fitting retrieval improved the measurement precision and stability. • Extremely low detection limit was achieved for aqueous ferrous measurement. • Iron in size segregated particulate matters shows seasonal characteristic. • More active role of iron was found in fine particles compared to coarse particles.

  14. Speciation of water soluble iron in size segregated airborne particulate matter using LED based liquid waveguide with a novel dispersive absorption spectroscopic measurement technique

    Energy Technology Data Exchange (ETDEWEB)

    Chan, K.L. [Meteorological Institute, Ludwig Maximilian University of Munich, Munich (Germany); School of Energy and Environment, City University of Hong Kong (Hong Kong); Jiang, S.Y.N. [School of Energy and Environment, City University of Hong Kong (Hong Kong); Ning, Z., E-mail: zhining@cityu.edu.hk [School of Energy and Environment, City University of Hong Kong (Hong Kong); Guy Carpenter Climate Change Centre, City University of Hong Kong (Hong Kong)

    2016-03-31

    In this study, we present the development and evaluation of a dispersive absorption spectroscopic technique for trace level soluble ferrous detection. The technique makes use of the broadband absorption spectra of the ferrous-ferrozine complex with a novel spectral fitting algorithm to determine soluble ferrous concentrations in samples and achieves much improved measurement precision compared to conventional methods. The developed method was evaluated by both model simulations and experimental investigations. The results demonstrated the robustness of the method against the spectral fluctuation, wavelength drift and electronic noise, while achieving excellent linearity (R{sup 2} > 0.999) and low detection limit (0.06 μg L{sup −1}) for soluble ferrous detection. The developed method was also used for the speciation of soluble iron in size segregated atmospheric aerosols. The measurement was carried out during Spring and Summer in typical urban environment in Hong Kong. The measured total iron concentrations are in good agreement compared to conventional Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES) measurements. Investigation on ambient particulate matter samples shows the size dependent characteristic of iron speciation in the atmosphere with a more active role of fine particles in transforming between ferrous and ferric. The method demonstrated in this study provides a cost and time effective approach for the speciation of iron in ambient aerosols. - Highlights: • Dispersive absorption spectroscopic technique for trace level ferrous detection. • The spectral fitting retrieval improved the measurement precision and stability. • Extremely low detection limit was achieved for aqueous ferrous measurement. • Iron in size segregated particulate matters shows seasonal characteristic. • More active role of iron was found in fine particles compared to coarse particles.

  15. Iron deficiency up-regulates iron absorption from ferrous sulphate but not ferric pyrophosphate and consequently food fortification with ferrous sulphate has relatively greater efficacy in iron-deficient individuals.

    Science.gov (United States)

    Zimmermann, Michael B; Biebinger, Ralf; Egli, Ines; Zeder, Christophe; Hurrell, Richard F

    2011-04-01

    Fe absorption from water-soluble forms of Fe is inversely proportional to Fe status in humans. Whether this is true for poorly soluble Fe compounds is uncertain. Our objectives were therefore (1) to compare the up-regulation of Fe absorption at low Fe status from ferrous sulphate (FS) and ferric pyrophosphate (FPP) and (2) to compare the efficacy of FS with FPP in a fortification trial to increase body Fe stores in Fe-deficient children v. Fe-sufficient children. Using stable isotopes in test meals in young women (n 49) selected for low and high Fe status, we compared the absorption of FPP with FS. We analysed data from previous efficacy trials in children (n 258) to determine whether Fe status at baseline predicted response to FS v. FPP as salt fortificants. Plasma ferritin was a strong negative predictor of Fe bioavailability from FS (P soluble Fe compounds not only demonstrate better overall absorption and can be used at lower fortification levels, but they also have the added advantage that, because their absorption is up-regulated in Fe deficiency, they innately 'target' Fe-deficient individuals in a population.

  16. In vitro dermal absorption of decabromodiphenyl ethane in rat and human skin

    Data.gov (United States)

    U.S. Environmental Protection Agency — In vitro dermal absorption of decabromodiphenyl ethane in rat and human skin. This dataset is associated with the following publication: Knudsen, G., J.M. Sanders,...

  17. Two-step milling on the carbonyl iron particles and optimizing on the composite absorption

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yonggang, E-mail: xuyonggang221@163.com [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai 200438 (China); Yuan, Liming; Wang, Xiaobing [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai 200438 (China); Zhang, Deyuan [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China)

    2016-08-15

    The flaky carbonyl iron particles (CIPs) were prepared using a two-step milling process. The surface morphology was characterized by the scanning electron microscopy, the static magnetic property was evaluated on a vibrating sample magnetometer and X-ray diffraction (XRD) patterns were done to analyze the particle crystal grain structure. The complex permittivity and permeability were measured using a vector network analyzer in the frequency range of 2–18 GHz. Then Hermite interpolation based on the calculated scattering parameters of the tested composite was used to derive the permittivity and permeability of the composite with random volume content. The results showed that the saturation magnetization value of the flaky CIPs decreased as the CIPs was changed to the flakes by high and low speeding milling. The diffraction peaks of the single α-Fe existed in the XRD pattern of CIPs, and the characteristic peaks was broad and the intensity of the diffraction pattern was lower as the high-speeding milling time increased. The sample H2L20 had the largest particle size, the average diameter was 8.64 μm, the thickness was 0.59 μm according to the fitted aspect ratio 14.65. The derived permittivity and permeability using the Hermite interpolation was accurate compared with the tested result, the deviation was about 0.39 + j0.45 and 2.5 + j0.51. Finally, the genetic algorithm was used to optimize the thickness of the CIPs composite of a wide absorbing band of 8–18 GHz. The optimized reflection loss (RL) result showed that the absorbing composites with thickness 1.47 mm had an excellent absorbing property (RL < −10 dB) in 8–18 GHz. - Graphical abstract: The property of absorber added two speeding milling CIPs could be enhanced using the genetic algorithm. - Highlights: • Flaky CIPs were prepared using a two-step milling process. • The permeability increased during the low speeding milling. • The aspect ratio of flaky CIPs increased in the optimized process

  18. Comparison between experimental and predicted specific absorption rate of functionalized iron oxide nanoparticle suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Yuan [Mechanical, Aerospace and Nuclear Engineering Department Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Tasciuc, Diana-Andra Borca, E-mail: borcad@rpi.edu [Mechanical, Aerospace and Nuclear Engineering Department Rensselaer Polytechnic Institute, Troy, NY 12180 (United States)

    2011-10-15

    Radio-frequency heated magnetic nanoaparticle suspensions have potential applications in cancer hyperthermia. To optimize these systems for hyperthermia applications it is important to be able to predict how their heat generation or specific absorption rate (SAR) is influenced by various factors, including nanoparticle coating or functionalization and aggregation. However, at present it is unclear how well-existing models predict experimental SAR results. Direct comparisons between predicted and measured SAR are scarce, despite an abundance of works reporting on heat generation rate of various magnetic nanoparticles suspensions. The main objective of this paper is to experimentally assess the validity of current models for SAR and extract information on the effects of coating and aggregation on heat generation rate. In this context, AC susceptibility and magnetization of suspensions of uncoated particles, as well as particles with aminosilane and carboxymethyl-dextran functionalizations, were measured. These properties were then used to predict the heat generation rate in alternating magnetic field starting from first principles, which was then compared to measured SAR. It was found that experimental SAR agrees relatively well with predictions (by a factor of two) when using experimental susceptibility values for the SAR calculation. However, for uncoated and amine-functionalized particles poor agreement (more than an order of magnitude difference) was found when the experimental susceptibility was substituted with predictions based on the Debye model. This apparent discrepancy is attributed to dipolar interactions between nanoparticles within aggregates in these samples, which enhances the imaginary part of the susceptibility and, consequently, the SAR values. The results also suggest that the thermal resistance effect of the coating has little influence on the SAR. - Highlights: > Thermal resistance of nanoparticle coating has little impact on heat dissipation

  19. Excellent improvement in the static and dynamic magnetic properties of carbon coated iron nanoparticles for microwave absorption

    Energy Technology Data Exchange (ETDEWEB)

    Khani, Omid, E-mail: omidkhani@mut-es.ac.ir; Shoushtari, Morteza Zargar; Farbod, Mansoor

    2015-11-15

    Carbon coated iron nanoparticles were synthesized, using a simple arc-discharge method. The morphology and the internal structure of the core/shell nanoparticles were studied, using field emission scanning electron microscopy and transmission electron microscopy. X-ray diffraction analysis showed that both magnetic α-Fe and nonmagnetic γ-Fe phases existed in the as-prepared particles. In order to improve the static and dynamic magnetic properties of the core/shell nanoparticles, the produced nanocapsules were annealed in argon atmosphere at two different temperatures. Hysteresis loops revealed that the value of the saturation magnetization (M{sub S}) increased more than 4.1 times of its original value by annealing and this led to 70% increase in the imaginary part of the permeability. Phase analysis showed that heat treatment eliminated the nonmagnetic γ-Fe phase completely. The reflection loss plots were studied for composite layers containing 20 vol% of the annealed and not annealed nanocapsules. One of the absorber layers which contained annealed nanocapsules showed at least −10 dB loss in the whole G, C, X and Ku frequency bands and the optimal absorption exceeded −37 dB at 5.8 GHz for the as-prepared sample with a thickness of 3.2 mm. The results revealed that the magnetic properties of the arc-made Fe/C core/shell nanoparticle can be improved significantly by annealing in argon.

  20. Determination of caesium in river and sea waters by electrothermal atomic-absorption spectrometry. Interference of cobalt and iron

    International Nuclear Information System (INIS)

    Frigieri, P.; Trucco, R.; Ciaccolini, I.; Pampurini, G.

    1980-01-01

    For the enrichment or the simple recovery of caesium from river and sea waters, selective inorganic exchangers were considered. Ammonium hexacyanocobalt ferrate (NCFC) was chosen because it can be used in strongly acidic solutions (with the exception of concentrated sulphuric acid). Caesium is fully retained by the NCFC chromatographic column and can then be recovered by dissolution in hot sulphuric acid. The solution is then diluted and analysed, either directly or following caesium separation, by atomic-absorption spectrometry. To check the reliability of the analytical procedure, a series of experiments were carried out in which the possible interfering species were added to the aqueous caesium solution prior to analysis. The well known ionic interference in flame atomisation processes caused by magnesium, calcium, strontium and metals was investigated by electrothermal atomisation measurements. The experimental data showed that this effect does not occur even when these elements are present in concentrations of the order of thousands of parts per million. However, strong interferences from iron and cobalt were observed. (author)

  1. Characterization and structural properties of iron in plants.

    Science.gov (United States)

    Dewanamuni, Udya; Dehipawala, Sunil; Gafney, Harry

    Iron is one of the most abundant metals in the soil and occurs in a wide range of chemical forms. Humans receive iron through either meat products or plants. Non meat eaters depend on plant product for their daily iron requirement. The iron absorption by plants depends on other minerals present in the soil and soil pH value. The amount of iron present in plants grown with different soil compositions were investigated using X-ray absorption spectroscopy (XAS) and Mossbauer spectroscopy. Based on the X-ray absorption data, the amount of iron in plants vary significantly with soil pH value. The Mossbauer spectroscopy reveals that iron present in the samples has the form Fe3+ or electron density at the site of the iron nucleus similar to that of Fe3+. CUNY Research Scholar Program, MSEIP.

  2. Absorption of iron in the aged; investigation of mucosal-uptake, mucosal-transfer and retention of a physiological dose of inorganic iron

    International Nuclear Information System (INIS)

    Marx, J.J.M.

    1976-01-01

    Iron (II) and iron (III) uptake by the mucosal cells, the retention in the body, and the mucosal-transport fraction were studied in 40 healthy people over 65 years old, in 30 young adults and in 20 patients with iron-deficiency. The study was performed with 59 Fe as a tracer and 51 Cr as an inert indicator. The radioactivity was measured with a whole body scanner 24 hours and 24 days after ingestion

  3. Theoretical interpretation for 2p − nd absorption spectra of iron, nickel, and copper in X-ray range measured at the LULI2000 facility

    Directory of Open Access Journals (Sweden)

    Poirier M.

    2013-11-01

    Full Text Available The 2p − nd absorption structures in medium Z elements present a valuable benchmark for atomic models since they exhibit a complex dependence on temperature and density. For these transitions lying in the X-ray range, one observes a competition between the spin-orbit splitting and the broadening associated to the excitation of complex structures. Detailed opacity codes based on the HULLAC or FAC suites agree with the statistical code SCO; but in iron computations predict higher peak absorption than measured. An addition procedure on opacities calculated with detailed codes is proposed and successfully tested.

  4. Isotope-aided studies of the bioavailability of iron and zinc from human diets consumed in Chile and Ecuador

    International Nuclear Information System (INIS)

    Hertrampf, E.; Pizarro, F.; Olivares, M.; Fuenmayor, G.; Yepes, R.; Soria, A.; Walter, T.

    1994-01-01

    Currently it is accepted that iron absorbed from infant formulas is less than 10%. However, the composition of such formulas has changed considerably and there is no recent information on the effects of these modifications. Iron bioavailability from infant formulas with different levels of iron fortification (8 and 12 mg of iron/L) and from a standard meal based on a wheat cream (''farina'' flour) was measured by a double radioisotopic technique (Eakins and Brown) in 13 adult female volunteers. Iron bioavailability in infant formulas was very high. Eighteen and 20.6 percent of the iron was absorbed in the 8 and 12 mg iron/L fortified formulas respectively (geometric means corrected to 40% of reference dose absorption). The corresponding value for iron absorption from the standard meal was 6.7%. These high and non significant differences in iron bioavailability from the two formulas and the fact that daily consumption of 750 ml of formula supplies more iron than recommended would permit a lowering of the current iron fortification level of 12 mg/L. Iron availability of the Standard Meal measured with FLAIR modifications of Miller's in vitro technique was 4.42%. The percentage of dialyzable zinc was 2.04%. Research activities for next year will be based on the validation and application of the in vitro technique in Chilean and Ecuadorian foods. (author). 26 refs, 4 tabs

  5. Isotope-aided studies of the bioavailability of iron and zinc from human diets consumed in Chile and Ecuador

    Energy Technology Data Exchange (ETDEWEB)

    Hertrampf, E; Pizarro, F; Olivares, M [Chile Univ., Santiago (Chile). Inst. de Nutricion y Tecnologia de los Alimentos (INTA); Fuenmayor, G; Yepes, R [Universidad Central del Ecuador, Quito (Ecuador). Lab. de Investigaciones en Metabolismo y Nutricion (LIMN); Soria, A [Carabobo Univ., Valencia (Venezuela). Facultad de Ciencias de la Salud; Walter, T

    1994-12-31

    Currently it is accepted that iron absorbed from infant formulas is less than 10%. However, the composition of such formulas has changed considerably and there is no recent information on the effects of these modifications. Iron bioavailability from infant formulas with different levels of iron fortification (8 and 12 mg of iron/L) and from a standard meal based on a wheat cream (``farina`` flour) was measured by a double radioisotopic technique (Eakins and Brown) in 13 adult female volunteers. Iron bioavailability in infant formulas was very high. Eighteen and 20.6 percent of the iron was absorbed in the 8 and 12 mg iron/L fortified formulas respectively (geometric means corrected to 40% of reference dose absorption). The corresponding value for iron absorption from the standard meal was 6.7%. These high and non significant differences in iron bioavailability from the two formulas and the fact that daily consumption of 750 ml of formula supplies more iron than recommended would permit a lowering of the current iron fortification level of 12 mg/L. Iron availability of the Standard Meal measured with FLAIR modifications of Miller`s in vitro technique was 4.42%. The percentage of dialyzable zinc was 2.04%. Research activities for next year will be based on the validation and application of the in vitro technique in Chilean and Ecuadorian foods. (author). 26 refs, 4 tabs.

  6. Microwave reflection, transmission, and absorption by human brain tissue

    Science.gov (United States)

    Ansari, M. A.; Akhlaghipour, N.; Zarei, M.; Niknam, A. R.

    2018-04-01

    These days, the biological effects of electromagnetic (EM) radiations on the brain, especially in the frequency range of mobile communications, have caught the attention of many scientists. Therefore, in this paper, the propagation of mobile phone electromagnetic waves in the brain tissues is investigated analytically and numerically. The brain is modeled by three layers consisting of skull, grey and white matter. First, we have analytically calculated the microwave reflection, transmission, and absorption coefficients using signal flow graph technique. The effect of microwave frequency and variations in the thickness of layers on the propagation of microwave through brain are studied. Then, the penetration of microwave in the layers is numerically investigated by Monte Carlo method. It is shown that the analytical results are in good agreement with those obtained by Monte Carlo method. Our results indicate the absorbed microwave energy depends on microwave frequency and thickness of brain layers, and the absorption coefficient is optimized at a number of frequencies. These findings can be used for comparing the microwave absorbed energy in a child's and adult's brain.

  7. Gastrointestinal absorption of neptunium and curium in humans

    International Nuclear Information System (INIS)

    Popplewell, D.S.; Harrison, J.D.; Ham, G.J.

    1991-01-01

    The gastrointestinal absorption of Np and Cm has been determined in five male adult volunteers. The Np and Cm, which were in citrate solution, were taken with food. An initial experiment with each individual determined the fraction of each element excreted in the urine following intravenous administration. Subsequently, the results for urinary excretion for the two routes of administration were used to calculate the fractional absorption (f1) of ingested Np and Cm. The mean f1 values were: Np (2.0 +/- 0.2) X 10 - 4 , range (1.2-2.9) X 10 - 4 , and Cm (1.7 +/- 0.3) X 10 - 4 , range (0.95-3.0) X 10 - 4 , the quoted uncertainties being the standard error of the means. Currently, the International Commission on Radiological Protection recommends a value of 10 - 3 for both elements. Cumulative urinary excretion over 1 wk after intravenous injection accounted for about 20%-40% of administered Np and 7%-10% of Cm. At the conclusion of the experiment, the total committed effective dose equivalent for each volunteer was calculated to be in the range 130-250 microSv, based on the individual f1 values, and, in some cases, a knowledge of the rate of clearance of 239 Np through the gut as measured by whole-body counting

  8. Human absorption and retention of polonium-210 from caribou meat.

    Science.gov (United States)

    Thomas, P A; Fisenne, I; Chorney, D; Baweja, A S; Tracy, B L

    2001-01-01

    The gastrointestinal (GI) absorption factors and the biological retention times for polonium were determined for a group of 14 volunteers--seven men and seven women--from Saskatoon, Saskatchewan, Canada. Each volunteer consumed 2.0 kg of caribou meat containing known amounts of naturally occurring 210Po. Urine and faecal samples were collected for up to 65 days after meat consumption and analysed for 210Po. The average GI absorption factor for the 14 volunteers was 56 +/- 4% (range = 31-71%), not significantly different from the ICRP value of 50%. About 3% of absorbed polonium underwent prompt excretion by the urinary pathway. The remainder was retained by the body with a half-time >100 days, compared to the ICRP value of 50 days. The effect of these findings increases the dose estimate for ingestion of 210Po in food by a factor of 1.5 to 3.5. Thus, background doses to people consuming caribou and reindeer may be higher than previously thought.

  9. Human absorption and retention of polonium-210 from caribou meat

    International Nuclear Information System (INIS)

    Thomas, P.A.; Fisenne, I.; Chorney, D.; Baweja, A.S.; Tracy, B.L.

    2001-01-01

    The gastrointestinal (GI) absorption factors and the biological retention times for polonium were determined for a group of 14 volunteers - seven men and seven women - from Saskatoon, Saskatchewan, Canada. Each volunteer consumed 2.0 kg of caribou meat containing known amounts of naturally occurring 210 Po. Urine and faecal samples were collected for up to 65 days after meat consumption and analysed for 210 Po. The average GI absorption factor for the 14 volunteers was 56±4% (range = 31-71%), not significantly different from the ICRP value of 50%. About 3% of absorbed polonium underwent prompt excretion by the urinary pathway. The remainder was retained by the body with a half-time >100 days, compared to the ICRP value of 50 days. The effect of these findings increases the dose estimate for ingestion of 210 Po in food by a factor of 1.5 to 3.5. Thus, background doses to people consuming caribou and reindeer may be higher than previously thought. (author)

  10. Elimination of the inter-element interferences of iron, gold, molybdenum, tin and antimony when determined in organic solvents by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Aneva, Zara; Arpadjan, Sonja

    1988-01-01

    The mutual interferences in the flame atomic absorption spectrometric determination of iron, gold, molybdenum, tin and antimony after their extraction - pre-concentration as chloride complexes from platinum solutions into isobutyl methyl ketone are investigated. It is suggested that the interferences are caused by chemical reactions in the flame and are influenced by the flame characteristics. The possibility of eliminating the interferences by addition of long-chain quaternary ammonium salts is discussed. (author)

  11. X-ray absorption spectroscopic studies of the dinuclear iron center in methane monooxygenase and the sulfure and chlorine centers in photographic materials

    Energy Technology Data Exchange (ETDEWEB)

    DeWitt, J.G.

    1992-12-01

    The dinuclear iron center of the hydroxylase component of soluble methane monooxygenase (MMO) from Methylococcus capsulatus and Methylosinus trichosporiwn has been studied by X-ray absorption spectroscopy. Analysis of the Fe K-edge EXAFS revealed that the first shell coordination of the Fe(HI)Fe(IH) oxidized state of the hydroxylase from M. capsulatus consists of approximately 6 N and 0 atoms at an average distance of 2.04 [Angstrom]. The Fe-Fe distance was determined to be 3.4 [Angstrom]. No evidence for the presence of a short oxo bridge in the iron center of the oxidized hydroxylase was found, suggesting that the active site of MMO is significantly different from the active sites of the dinuclear iron proteins hemery and ribonucleotide reductase. In addition, the results of the first shell fits suggest that there are more oxygen than nitrogen donor ligands.

  12. X-ray absorption spectroscopic studies of the dinuclear iron center in methane monooxygenase and the sulfure and chlorine centers in photographic materials

    Energy Technology Data Exchange (ETDEWEB)

    DeWitt, Jane G. [Stanford Univ., CA (United States)

    1992-12-01

    The dinuclear iron center of the hydroxylase component of soluble methane monooxygenase (MMO) from Methylococcus capsulatus and Methylosinus trichosporiwn has been studied by X-ray absorption spectroscopy. Analysis of the Fe K-edge EXAFS revealed that the first shell coordination of the Fe(HI)Fe(IH) oxidized state of the hydroxylase from M. capsulatus consists of approximately 6 N and 0 atoms at an average distance of 2.04 Å. The Fe-Fe distance was determined to be 3.4 Å. No evidence for the presence of a short oxo bridge in the iron center of the oxidized hydroxylase was found, suggesting that the active site of MMO is significantly different from the active sites of the dinuclear iron proteins hemery and ribonucleotide reductase. In addition, the results of the first shell fits suggest that there are more oxygen than nitrogen donor ligands.

  13. Preconcentration and atomic absorption spectrometric determination of cadmium, cobalt, copper, iron, lead, manganese, nickel and zinc in water samples using 6-methyl-2-pyridinecarboxaldehyde-4-phenyl-3-thiosemicarbazone

    International Nuclear Information System (INIS)

    Khuhawar, M.Y.; Das, P.; Dewani, V.K.

    2005-01-01

    The reagent 6-methyl-2-pyridinecarboxaldehyde-4-phenyl-3-thiosemicarbazone (MPAPT) has been examined for the pre-concentration of metal ions and determination using air acetylene flame atomic absorption spectrometer. The method is based on the complexation and extraction of cadmium (II), cobalt(III), copper(II), lead(II), nickel(II), iron(II), iron(II), manganese(II) and zinc(II) in chloroform. The metal iron are back extracted in nitric acid (1:1) or after evaporation of solvent the residue is digested in nitric acid. After necessary adjustment of volume the metal ions were determined in aqueous solution. Pre-concentration is obtained 10-25 times. Metal ions recovery was 95.4-100.8% with coefficient of variation 0.2-7.5%. The method used for the determination of metals in canal and sewerage waters, within 2-6433 mu g/L with C. V 0.-5.2%. (author)

  14. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... deficiency anemia. Proton pump inhibitors interfere with iron absorption, and blood thinners increase the likelihood of bleeding ... oranges, strawberries, and tomatoes, may help increase your absorption of iron. If you are pregnant, talk to ...

  15. Response of human lymphoblastoid cells to HZE (iron ions) or gamma-rays

    Data.gov (United States)

    National Aeronautics and Space Administration — Transcriptional profiling of human lymphoblastoid TK6 cells comparing mock irradiated cells with cells exposed 24 hours previously to 1.67 Gy HZE (1 GeV/amu iron...

  16. Use of radioisotopes in studying iron metabolism in humans in Sri Lanka

    International Nuclear Information System (INIS)

    Liyanage, C.E.; Thabrew, M.I.

    1994-01-01

    Anaemia due to iron deficiency is the commonest haematological problem found in Sri Lankan pregnant women and pre-school children. The reported prevalence rates amongst pregnant and lactating women ranged from 60-80%. The present study revealed that 3% of pregnant women had satisfactory iron stores and 57% had virtually no iron stores. Routine iron supplementation is justified not only to correct the anaemia but also to build up the maternal iron stores. In a longitudinal study of 100 pregnant women a very high prevalence was observed in spite of the fact that the population studied was on iron supplementation. A very poor compliance on iron therapy was seen. The incidence of low birth weight observed was 32%, quite similar to that has been reported previously for Sri Lanka. Therefore, further longitudinal studies have been designed to find out the efficacy of the present supplementary programme. In Galle District 54.5% of the pre-school children were found clearly anaemic and another 20% had evidence of iron depletion. As the dietary intake of iron was marginal, the weaning foods that are in practice were tested for iron availability. Iron absorption/availability studies by in-vivo (extrinsic tag method) and in-vitro (using radioiron 59 Fe tracer) methods have shown a very poor (less than 5%) availability in many of the commonly used weaning foods. A statistically significant decrease in iron availability was seen with increase in amount of polyphenols mainly in some of the preparations made with green leaves. Addition of ascorbic acid rich food items showed an increase in iron availability (by 2-6 times). Dietary zinc intake of 46 children (2-5 yrs) was found 2-4 mg/1000 kcal, relating to total energy intake. Mean plasma zinc concentration of these children was 13.8±0.8 μmol/L. Therefore further studies on the improvement of zinc and iron availability in weaning foods have been designed to be done in future. (author). 3 refs, 1 fig

  17. Subcutaneous insulin absorption explained by insulin's physicochemical properties. Evidence from absorption studies of soluble human insulin and insulin analogues in humans.

    Science.gov (United States)

    Kang, S; Brange, J; Burch, A; Vølund, A; Owens, D R

    1991-11-01

    To study the influence of molecular aggregation on rates of subcutaneous insulin absorption and to attempt to elucidate the mechanism of absorption of conventional soluble human insulin in humans. Seven healthy male volunteers aged 22-43 yr and not receiving any drugs comprised the study. This study consisted of a single-blind randomized comparison of equimolar dosages of 125I-labeled forms of soluble hexameric 2 Zn2+ human insulin and human insulin analogues with differing association states at pharmaceutical concentrations (AspB10, dimeric; AspB28, mixture of monomers and dimers; AspB9, GluB27, monomeric). After an overnight fast and a basal period of 1 h, 0.6 nmol/kg of either 125I-labeled human soluble insulin (Actrapid HM U-100) or 125I-labeled analogue was injected subcutaneously on 4 separate days 1 wk apart. Absorption was assessed by measurement of residual radioactivity at the injection site by external gamma-counting. The mean +/- SE initial fractional disappearance rates for the four preparations were 20.7 +/- 1.9 (hexameric soluble human insulin), 44.4 +/- 2.5 (dimeric analogue AspB10), 50.6 +/- 3.9 (analogue AspB28), and 67.4 +/- 7.4%/h (monomeric analogue AspB9, GluB27). Absorption of the dimeric analogue was significantly faster than that of hexameric human insulin (P less than 0.001); absorption of monomeric insulin analogue AspB9, GluB27 was significantly faster than that of dimeric analogue AspB10 (P less than 0.01). There was an inverse linear correlation between association state and the initial fractional disappearance rates (r = -0.98, P less than 0.02). Analysis of the disappearance data on a log linear scale showed that only the monomeric analogue had a monoexponential course throughout. Two phases in the rates of absorption were identified for the dimer and three for hexameric human insulin. The fractional disappearance rates (%/h) calculated by log linear regression analysis were monomer 73.3 +/- 6.8; dimer 44.4 +/- 2.5 from 0 to 2 h and

  18. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... drinking black tea, which reduces iron absorption. Other treatments If you have chronic kidney disease and iron- ... and lifestyle changes to avoid complications. Follow your treatment plan Do not stop taking your prescribed iron ...

  19. Absorption and excretion of black currant anthocyanins in human and Watanabe Heritable Hyperlipidemic rabbits

    DEFF Research Database (Denmark)

    Nielsen, I. L.. F.; Ravn-Haren, Gitte; Dragsted, L. O.

    2003-01-01

    Anthocyanins are thought to protect against cardiovascular diseases. Watanabe heritable hyperlipidemic (WHHL) rabbits are hypercholesterolemic and used as a model of the development of atherosclerosis. To compare the uptake and excretion of anthocyanins in humans and WHHL rabbits, single-dose black......). The excretion and absorption of anthocyanins from black currant juice were found to be within the same order of magnitude in the two species regarding urinary excretion within the first 4 h (rabbits, 0.035%; humans, 0.072%) and t(ma)x (rabbits, similar to30 min; humans, similar to45 min). A food matrix effect...... was detected in rabbits, resulting in the absorption of a higher proportion of the anthocyanins from black currant juice than from an aqueous citric acid matrix. In humans the absorption and urinary excretion of anthocyanins from black currant juice were found to be proportional with dose and not influenced...

  20. A new approach to predict human intestinal absorption using porcine intestinal tissue and biorelevant matrices

    NARCIS (Netherlands)

    Westerhout, J.; Steeg, E. van de; Grossouw, D.; Zeijdner, E.E.; Krul, C.A.M.; Verwei, M.; Wortelboer, H.M.

    2014-01-01

    A reliable prediction of the oral bioavailability in humans is crucial and of high interest for pharmaceutical and food industry. The predictive value of currently used in silico methods, in vitro cell lines, ex vivo intestinal tissue and/or in vivo animal studies for human intestinal absorption,

  1. The effect of lipids, a lipid-rich ready-to-use therapeutic food, or a phytase on iron absorption from maize-based meals fortified with micronutrient powders.

    Science.gov (United States)

    Monnard, Arnaud; Moretti, Diego; Zeder, Christophe; Steingötter, Andreas; Zimmermann, Michael B

    2017-06-01

    Background: Ready-to-use-therapeutic foods (RUTFs) high in lipid, protein, and iron are used to treat malnutrition. Lipids increase gastric residence time, which could increase iron absorption, particularly from poorly soluble iron compounds and in combination with phytase. Objectives: The objectives were to 1 ) assess the effect on iron absorption of a lipid emulsion given 20 min before or together with an iron-fortified maize meal and 2 ) assess iron absorption from a micronutrient powder (MNP) given with a nutrient-dense RUTF and/or a microbial phytase. Design: A total of 41 women participated in 3 studies. They consumed a maize meal fortified with isotopically labeled ferrous sulfate (FeSO 4 ; study 1) or ferric pyrophosphate (FePP; study 2). In studies 1 and 2, a lipid emulsion was given with or 20 min before the meal. In study 3, with the use of a 2 × 2 factorial design, subjects consumed a maize meal fortified with an MNP containing labeled FeSO 4 (MNP) given with an RUTF (MNP+RUTF), with a phytase (MNP+phytase), or both (MNP+RUTF+phytase). Iron absorption was assessed by isotope incorporation in erythrocytes 14 d after the test meals. Results: The lipid emulsion given either before or with the meal significantly increased iron absorption from FePP by 2.55-fold (95% CI: 1.48-, 4.37-fold; P = 0.001) but not from FeSO 4 There was a trend to increase iron absorption with the MNP+RUTF meal, which did not reach significance (1.21-fold; 95% CI: 0.92-, 1.61-fold; P = 0.060). The addition of phytase to MNP and MNP+RUTF significantly increased iron absorption by 1.85-fold (95% CI: 1.49-, 2.29-fold; P phytase and RUTF. Conclusions: In iron-fortified maize-based meals, the addition of lipids more than doubles iron absorption from FePP. Our results suggest the possibility of an enhancing effect on iron absorption of lipid-rich RUTFs, but more research is needed to determine this. This trial was registered at clinicaltrials.gov as NCT01991626. © 2017 American Society

  2. Mechanistic understanding of time-dependent oral absorption based on gastric motor activity in humans.

    Science.gov (United States)

    Higaki, Kazutaka; Choe, Sally Y; Löbenberg, Raimar; Welage, Lynda S; Amidon, Gordon L

    2008-09-01

    The relationship of gastric motor activity and gastric emptying of 0.7 mm caffeine pellets with their absorption was investigated in the fed state in healthy human subjects by simultaneous monitoring of antral motility and plasma concentrations. A kinetic model for gastric emptying-dependent absorption yielded multiple phases of gastric emptying and rate constants (k(g)) with large inter-individual differences and large variability in onset of gastric emptying (50-175 min). The model suggests that 50% of the dose is emptied in 1-2h and over 90% emptied by 3.5h following dosing, in all subjects. The maximum values of k(g) (k(g)(max)) were much greater than those reported for emptying of liquids in the fasted state and were comparable to k(g) values in the late Phase II/III of the migrating motor complex (MMC). The model described the observed irregular absorption rate-time and plasma concentration-time profiles adequately but not in detail. The model was more successful at simulating double-peak phenomena in absorption rate profiles and onset of caffeine absorption. The results suggest that gastric emptying regulates drug absorption of small particles in the fed state. Further, estimates of k(a) derived using the time-dependent absorption model were closer to the intrinsic absorption rate constant for caffeine.

  3. Effects of Iron Concentration Level in Extracting Solutions from Contaminated Soils on the Determination of Zinc by Flame Atomic Absorption Spectrometry with Two Background Correctors

    Directory of Open Access Journals (Sweden)

    Christophe Waterlot

    2012-01-01

    Full Text Available Zinc and iron concentrations were determined after digestion, water, and three-step sequential extractions of contaminated soils. Analyses were carried out using flame absorption spectrometry with two background correctors: a deuterium lamp used as the continuum light source (D2 method and the high-speed self-reversal method (HSSR method. Regarding the preliminary results obtained with synthetic solutions, the D2 method often emerged as an unsuitable configuration for compensating iron spectral interferences. In contrast, the HSSR method appeared as a convenient and powerful configuration and was tested for the determination of zinc in contaminated soils containing high amounts of iron. Simple, fast, and interference-free method, the HSSR method allows zinc determination at the ppb level in the presence of large amounts of iron with high stability, sensitivity, and reproducibility of results. Therefore, the HSSR method is described here as a promising approach for monitoring zinc concentrations in various iron-containing samples without any pretreatment.

  4. Determination of antimony by electrochemical hydride generation atomic absorption spectrometry in samples with high iron content using chelating resins as on-line removal system

    International Nuclear Information System (INIS)

    Bolea, E.; Arroyo, D.; Laborda, F.; Castillo, J.R.

    2006-01-01

    A method for the removal of the interference caused by iron on electrochemical generation of stibine is proposed. It consists of a chelating resin Chelex 100 column integrated into a flow injection system and coupled to the electrochemical hydride generator quartz tube atomic absorption spectrometer (EcHG-QT-AAS). Iron, as Fe(II), is retained in the column with high efficiency, close to 99.9% under optimal conditions. No significant retention was observed for Sb(III) under same conditions and a 97 ± 5% signal recovery was achieved. An electrochemical hydride generator with a concentric configuration and a reticulated vitreous carbon cathode was employed. The system is able to determine antimony concentrations in the range of ng ml -1 in presence of iron concentrations up to 400 mg l -1 . The procedure was validated by analyzing PACS-2 marine sediments reference material with a 4% (w/w) iron content and a [Fe]:[Sb] ratio of 4000:1, which caused total antimony signal suppression on the electrochemical hydride generation system. A compost sample with high iron content (0.7%, w/w), was also analyzed. A good agreement was found on both samples with the certified value and the antimony concentration determined by ICP-MS, respectively

  5. A pre-concentration procedure using coprecipitation for determination of lead and iron in several samples using flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Saracoglu, S.; Soylak, M.; Peker, D.S. Kacar; Elci, L.; Santos, W.N.L. dos; Lemos, V.A.; Ferreira, S.L.C.

    2006-01-01

    The present paper proposes a pre-concentration procedure for determination of lead and iron in several samples by flame atomic absorption spectrometry. In it, lead(II) and iron(III) ions are coprecipitated using the violuric acid-copper(II) system as collector. Afterwards, the precipitate is dissolved with 1 M HNO 3 solution and the metal ions are determined. The optimization step was performed using factorial design involving the variables: pH, violuric acid mass (VA) and copper concentration (Cu). Using the optimized experimental conditions, the proposed procedure allows the determination these metals with detection limits of 0.18 μg L -1 for iron and 0.16 μg L -1 for lead. The effects of foreign ions on the pre-concentration procedure were also evaluated and the results demonstrated that this method could be applied for determination of iron and lead in several real samples. The proposed method was successfully applied to the analysis of seawater, urine, mineral water, soil and physiological solution samples. The concentrations of lead and iron achieved in these samples agree well with others data reported in the literature

  6. Uranium gastrointestinal absorption: the F1 factor in humans

    International Nuclear Information System (INIS)

    Zamora, M.L.; Zielinski, J.M.; Meyerhof, D.; Moodie, G.; Falcomer, R.; Tracy, B.

    2003-01-01

    The present investigation was undertaken by the Department of Health, Canada, to determine the most appropriate value to use for uranium gastrointestinal absorption (f 1 ) in setting the guideline for drinking water. Fifty participants, free from medical problems, were recruited from two communities: a rural area where drinking water, supplied from drilled wells, contained elevated levels of uranium and an urban area where the water supplied by the municipal water system contained -1 . Uranium intake through food, drinking water and other beverages was monitored using the duplicate diet approach. Intake and excretion were measured by inductively coupled plasma-mass spectrometry (ICP-MS) in samples collected concurrently from the same individuals over a 3 d period. The range of f 1 values was between 0.001 to 0.06, with a median of 0.009. These values were independent of gender, age, duration of exposure, daily total uranium intake and allocation of intake between food and water. Consistent with the recommendation of ICRP Publication 69, 78% were below 0.02. (author)

  7. The role of p97 in iron metabolism in human brain glioma cells

    International Nuclear Information System (INIS)

    Xia Chunlin; Chen Guiwen; Qian Zhongming

    2000-01-01

    Objective: To investigate the role of p97 (melanotransferrin) in iron uptake in human brain glioma cells . Methods: Human brain glioma cell lines, GBM and BT325 were incubated in the medium containing 59 Fe-Citrate. The cells were treated with phosphatidylinositol-phospholipase C (PI-PLC) and pronase. The iron uptake of the cells was expressed as relative iron uptake level according to the cpm measured by the gamma scintillation counter. Results: 59 Fe uptake of the cells was significantly declined with the certain concentration of PI-PCL. 59 Fe uptake of the cells treated with pronase tended to coincide with that of the cells treated without pronase in the increasing concentration of PI-PLC. Conclusion: p97 expresses a high level and plays an important role in iron uptake in human brain glioma cells

  8. FDI spillovers, absorptive capacities and human capital development

    DEFF Research Database (Denmark)

    Narula, Rajneesh; Marin, Anabel

    2003-01-01

    spillovers accrue from MNE activity, and provide apreliminary understanding of why MNE spillovers remain somewhat ambiguous,particularly in developing countries, paying particular attention to human capitaldevelopment. Our analysis is supported by data from the Innovation Survey in Argentina.On the whole......It is nowadays generally accepted that inward foreign direct investment (FDI) is crucialas a source of technological spillovers. One of the objectives of this paper is to review theevidence on the quantity and quality of human capital employed by domestic and foreignfirms. We examine whether...

  9. Comprehensive study of the effects of age, iron deficiency, diabetes mellitus, and cadmium burden on dietary cadmium absorption in cadmium-exposed female Japanese farmers

    International Nuclear Information System (INIS)

    Horiguchi, Hyogo; Oguma, Etsuko; Sasaki, Satoshi; Miyamoto, Kayoko; Ikeda, Yoko; Machida, Munehito; Kayama, Fujio

    2004-01-01

    The absorption rate of dietary cadmium (Cd) was investigated among 38 female farmers who had been exposed to Cd at levels close to the current provisional tolerable weekly intake (PTWI); these levels were much higher than those examined in previous studies. The study group composed of 7 diabetics and their 13 age-matched controls and 6 anemic subjects and their 12 controls. With their informed consent, the study participants were confined in an inn for 7 nights and 8 days to collect all feces and urine and duplicates of all food consumed. The dietary Cd absorption rate was calculated for each subject from her total Cd intake and fecal excretion. The means and 95% confidence intervals (CI) of the diabetic group and the anemic group did not differ significantly from those of their respective controls. By individual analysis using all 38 subjects, however, significant Pearson's correlation coefficients were observed between Cd absorption rate and age, serum ferritin, serum iron, and blood and urine Cd levels. Among these, multiple regression analysis revealed that only age was a significant factor contributing to Cd absorption rate. The actual Cd absorption rate in the youngest age group (20-39 years) was 44.0%, which was highly accelerated compared with the rate in the total subject group of 6.5%, while zero to negative balance was observed in the older subjects. These results demonstrate that age, rather than iron deficiency, diabetes mellitus (DM), or Cd burden, is the only independent factor affecting the Cd absorption rate, suggesting that young women are always at high risk

  10. Iron concentrations in breast milk and selected maternal factors of human milk bank donors.

    Science.gov (United States)

    Mello-Neto, Julio; Rondó, Patrícia H C; Morgano, Marcelo A; Oshiiwa, Marie; Santos, Mariana L; Oliveira, Julicristie M

    2010-05-01

    The aim of this study was to evaluate the relationship between iron concentration in mature breast milk and characteristics of 136 donors of a Brazilian milk bank. Iron, vitamin A, zinc, and copper concentrations were assessed in human milk and maternal blood. Data were collected on maternal anthropometrics, obstetric, socioeconomic, demographic, and lifestyle factors. Iron, zinc, and copper in milk and zinc and copper in blood were detected by spectrophotometry. Vitamin A in milk and blood was determined by high-performance liquid chromatography. Hemoglobin was measured by electronic counting and serum iron and ferritin by colorimetry and chemoluminescence, respectively. Transferrin and ceruloplasmin were determined by nephelometry. According to multivariate linear regression analysis, iron in milk was positively associated with vitamin A in milk and with smoking but negatively associated with timing of breast milk donation (P milk of Brazilian donors may be influenced by nutritional factors and smoking.

  11. Potential of Phytase-Mediated Iron Release from Cereal-Based Foods: A Quantitative View

    Science.gov (United States)

    Nielsen, Anne V. F.; Tetens, Inge; Meyer, Anne S.

    2013-01-01

    The major part of iron present in plant foods such as cereals is largely unavailable for direct absorption in humans due to complexation with the negatively charged phosphate groups of phytate (myo-inositol (1,2,3,4,5,6)-hexakisphosphate). Human biology has not evolved an efficient mechanism to naturally release iron from iron phytate complexes. This narrative review will evaluate the quantitative significance of phytase-catalysed iron release from cereal foods. In vivo studies have shown how addition of microbially derived phytases to cereal-based foods has produced increased iron absorption via enzyme-catalysed dephosphorylation of phytate, indicating the potential of this strategy for preventing and treating iron deficiency anaemia. Despite the immense promise of this strategy and the prevalence of iron deficiency worldwide, the number of human studies elucidating the significance of phytase-mediated improvements in iron absorption and ultimately in iron status in particularly vulnerable groups is still low. A more detailed understanding of (1) the uptake mechanism for iron released from partially dephosphorylated phytate chelates, (2) the affinity of microbially derived phytases towards insoluble iron phytate complexes, and (3) the extent of phytate dephosphorylation required for iron release from inositol phosphates is warranted. Phytase-mediated iron release can improve iron absorption from plant foods. There is a need for development of innovative strategies to obtain better effects. PMID:23917170

  12. [Dinitrosyl iron complexes are endogenous signaling agents in animal and human cells and tissues (a hypothesis)].

    Science.gov (United States)

    Vanin, A F

    2004-01-01

    The hypothesis was advanced that dinitrosyl iron complexes generated in animal and human cells and tissues producing nitric oxide can function as endogenous universal regulators of biochemical and physiological processes. This function is realized by the ability of dinitrosyl iron complexes to act as donors of free nitric oxide molecules interacting with the heme groups of proteins, nitrosonium ions, or Fe+(NO+)2 interacting with the thiol groups of proteins. The effect of dinitrosyl iron complexes on the activity of some enzymes and the expression of the genome at the translation and transcription levels was considered.

  13. Potential of phytase-mediated iron release from cereal-based foods: a quantitative view

    DEFF Research Database (Denmark)

    Nielsen, Anne Veller Friis; Tetens, Inge; Meyer, Anne S.

    2013-01-01

    The major part of iron present in plant foods such as cereals is largely unavailable for direct absorption in humans due to complexation with the negatively charged phosphate groups of phytate (myo-inositol (1,2,3,4,5,6)-hexakisphosphate). Human biology has not evolved an efficient mechanism...... to naturally release iron from iron phytate complexes. This narrative review will evaluate the quantitative significance of phytase-catalysed iron release from cereal foods. In vivo studies have shown how addition of microbially derived phytases to cereal-based foods has produced increased iron absorption via...... phytate complexes, and (3) the extent of phytate dephosphorylation required for iron release from inositol phosphates is warranted. Phytase-mediated iron release can improve iron absorption from plant foods. There is a need for development of innovative strategies to obtain better effects....

  14. An inulin-type fructan enhances calcium absorption primarily via an effect on colonic absorption in humans

    Science.gov (United States)

    Calcium absorption efficiency and bone mineral mass are increased in adolescents who regularly consume inulin-type fructans (ITF). The mechanism of action in increasing absorption is unknown but may be related to increased colonic calcium absorption. We conducted a study in young adults designed to ...

  15. Simultaneous determination of cadmium, iron and tin in canned foods using high-resolution continuum source graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Leao, Danilo J; Junior, Mario M S; Brandao, Geovani C; Ferreira, Sergio L C

    2016-06-01

    A method was established to simultaneously determine cadmium, iron and tin in canned-food samples using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS). The quantification step has been performed using the primary line (228.802nm) for cadmium and the adjacent secondary lines (228.725nm and 228.668nm) for iron and tin, respectively. The selected chemical modifier was an acid solution that contained a mixture of 0.1% (w/v) Pd and 0.05% (w/v) Mg. The absorbance signals were measured based on the peak area using 3 pixels for cadmium and 5 pixels for iron and tin. Under these conditions, cadmium, iron and tin have been determined in canned-food samples using the external calibration technique based on aqueous standards, where the limits of quantification were 2.10ngg(-1) for cadmium, 1.95mgkg(-1) for iron and 3.00mgkg(-1) for tin, and the characteristic masses were 1.0pg for cadmium, 0.9ng for iron and 1.1ng for tin. The precision was evaluated using two solutions of each metal ion, and the results, which were expressed as the relative standard deviation (RSD%), were 3.4-6.8%. The method accuracy for cadmium and iron was confirmed by analyzing a certified reference material of apple leaves (NIST 1515), which was supplied by NIST. However, for tin, the accuracy was confirmed by comparing the results of the proposed method and another analytical technique (inductively coupled plasma optical emission spectrometry). The proposed procedure was applied to determine cadmium, iron and tin in canned samples of peeled tomato and sardine. Eleven samples were analyzed, and the analyte concentrations were 3.57-62.9ngg(-1), 2.68-31.48mgkg(-1) and 4.06-122.0mgkg(-1) for cadmium, iron and tin, respectively. In all analyzed samples, the cadmium and tin contents were lower than the permissible maximum levels for these metals in canned foods in the Brazilian legislation. Copyright © 2016. Published by Elsevier B.V.

  16. Preconcentration and determination of iron and copper in spice samples by cloud point extraction and flow injection flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Cigdem Arpa, E-mail: carpa@hacettepe.edu.tr [Hacettepe University, Chemistry Department, 06800 Beytepe, Ankara (Turkey); Tokgoez, Ilknur; Bektas, Sema [Hacettepe University, Chemistry Department, 06800 Beytepe, Ankara (Turkey)

    2010-09-15

    A flow injection (FI) cloud point extraction (CPE) method for the determination of iron and copper by flame atomic absorption spectrometer (FAAS) has been improved. The analytes were complexed with 3-amino-7-dimethylamino-2-methylphenazine (Neutral Red, NR) and octylphenoxypolyethoxyethanol (Triton X-114) was added as a surfactant. The micellar solution was heated above 50 {sup o}C and loaded through a column packed with cotton for phase separation. Then the surfactant-rich phase was eluted using 0.05 mol L{sup -1} H{sub 2}SO{sub 4} and the analytes were determined by FAAS. Chemical and flow variables influencing the instrumental and extraction conditions were optimized. Under optimized conditions for 25 mL of preconcentrated solution, the enrichment factors were 98 and 69, the limits of detection (3s) were 0.7 and 0.3 ng mL{sup -1}, the limits of quantification (10s) were 2.2 and 1.0 ng mL{sup -1} for iron and copper, respectively. The relative standard deviation (RSD) for ten replicate measurements of 10 ng mL{sup -1} iron and copper were 2.1% and 1.8%, respectively. The proposed method was successfully applied to determination of iron and copper in spice samples.

  17. The effect of proteins from animal source foods on heme iron bioavailability in humans.

    Science.gov (United States)

    Pizarro, Fernando; Olivares, Manuel; Valenzuela, Carolina; Brito, Alex; Weinborn, Valerie; Flores, Sebastián; Arredondo, Miguel

    2016-04-01

    Forty-five women (35-45 year) were randomly assigned to three iron (Fe) absorption sub-studies, which measured the effects of dietary animal proteins on the absorption of heme Fe. Study 1 was focused on heme, red blood cell concentrate (RBCC), hemoglobin (Hb), RBCC+beef meat; study 2 on heme, heme+fish, chicken, and beef; and study 3 on heme and heme+purified animal protein (casein, collagen, albumin). Study 1: the bioavailability of heme Fe from Hb was similar to heme only (∼13.0%). RBCC (25.0%) and RBCC+beef (21.3%) were found to be increased 2- and 1.6-fold, respectively, when compared with heme alone (pProteins from animal source foods and their digestion products did not enhance heme Fe absorption. Copyright © 2015. Published by Elsevier Ltd.

  18. Absorption mechanisms for cationic and anionic mineral species on ferric iron polymer hydroxides and oxidation products of ferrous iron in aqueous media

    International Nuclear Information System (INIS)

    Gandon, Remi

    1982-01-01

    Adsorbents obtained by hydrolysing the Fe 3+ , 6H 2 O ion are made of polymers with aquo (H 2 O), hydroxo (-OH...) and oxo (...O...) ligands. Radioactive tracers reveal the importance of chemical mechanisms in adsorption phenomena on ferric oxide in aqueous media. Zn 2+ , Co 2+ and Mn 2+ cations are exchanged with hydrogen from hydroxo groups. CrO 4 2- , SeO 3 2- and Sb(OH) 6 - anions form covalent associations in place of iron ligands. The adsorption of hydrolyzed ions results in strong oxygen bridge bonds. In fresh water, Co and Mn participate alone in physical electrostatic adsorption. Iron II oxidation products generate chemical adsorptions. Zn 2+ and Sb(OH) 6 - associate with ferric hydroxides from oxidized Fe 2+ . 60 Co, 54 Mn and 51 Cr form covalent associations between unpaired 3d iron electrons and the adsorbed element. This process is not predominant with selenium IV or VI reduced to the metallic state or fixed on ferric hydroxide in the selenite form. These conclusions can be applied to pollutant analysis and to water purification and contribute to our understanding of the role of iron in the distribution of oligo-elements in aqueous media. (author) [fr

  19. Prediction of Human Intestinal Absorption of Compounds Using Artificial Intelligence Techniques.

    Science.gov (United States)

    Kumar, Rajnish; Sharma, Anju; Siddiqui, Mohammed Haris; Tiwari, Rajesh Kumar

    2017-01-01

    Information about Pharmacokinetics of compounds is an essential component of drug design and development. Modeling the pharmacokinetic properties require identification of the factors effecting absorption, distribution, metabolism and excretion of compounds. There have been continuous attempts in the prediction of intestinal absorption of compounds using various Artificial intelligence methods in the effort to reduce the attrition rate of drug candidates entering to preclinical and clinical trials. Currently, there are large numbers of individual predictive models available for absorption using machine learning approaches. Six Artificial intelligence methods namely, Support vector machine, k- nearest neighbor, Probabilistic neural network, Artificial neural network, Partial least square and Linear discriminant analysis were used for prediction of absorption of compounds. Prediction accuracy of Support vector machine, k- nearest neighbor, Probabilistic neural network, Artificial neural network, Partial least square and Linear discriminant analysis for prediction of intestinal absorption of compounds was found to be 91.54%, 88.33%, 84.30%, 86.51%, 79.07% and 80.08% respectively. Comparative analysis of all the six prediction models suggested that Support vector machine with Radial basis function based kernel is comparatively better for binary classification of compounds using human intestinal absorption and may be useful at preliminary stages of drug design and development. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  20. Role of brain iron accumulation in cognitive dysfunction: evidence from animal models and human studies.

    Science.gov (United States)

    Schröder, Nadja; Figueiredo, Luciana Silva; de Lima, Maria Noêmia Martins

    2013-01-01

    Over the last decades, studies from our laboratory and other groups using animal models have shown that iron overload, resulting in iron accumulation in the brain, produces significant cognitive deficits. Iron accumulation in the hippocampus and the basal ganglia has been related to impairments in spatial memory, aversive memory, and recognition memory in rodents. These results are corroborated by studies showing that the administration of iron chelators attenuates cognitive deficits in a variety of animal models of cognitive dysfunction, including aging and Alzheimer's disease models. Remarkably, recent human studies using magnetic resonance image techniques have also shown a consistent correlation between cognitive dysfunction and iron deposition, mostly in the hippocampus, cortical areas, and basal ganglia. These findings may have relevant implications in the light of the knowledge that iron accumulates in brain regions of patients suffering from neurodegenerative diseases. A better understanding of the functional consequences of iron dysregulation in aging and neurological diseases may help to identify novel targets for treating memory problems that afflict a growing aging population.

  1. Characterisation of human skin models - stability, metabolic capacity and comparative investigations in percutaneous absorption

    OpenAIRE

    Schreiber, Sylvia

    2010-01-01

    In recent years, the demand for alternative test methods in safety assessment of cosmetics, risk assessment of chemicals, and testing of pharmaceuticals was increasingly included in the EU directives. Thereby, alternative test methods for the determination of percutaneous absorption should achieve a more reliable in vivo prediction of the response of human skin than animal skin. Even though freshly excised human skin is considered as a preferred test matrix its routine use is often difficult ...

  2. Iron phosphate nanoparticles for food fortification: Biological effects in rats and human cell lines.

    Science.gov (United States)

    von Moos, Lea M; Schneider, Mirjam; Hilty, Florentine M; Hilbe, Monika; Arnold, Myrtha; Ziegler, Nathalie; Mato, Diogo Sales; Winkler, Hans; Tarik, Mohamed; Ludwig, Christian; Naegeli, Hanspeter; Langhans, Wolfgang; Zimmermann, Michael B; Sturla, Shana J; Trantakis, Ioannis A

    2017-05-01

    Nanotechnology offers new opportunities for providing health benefits in foods. Food fortification with iron phosphate nanoparticles (FePO 4 NPs) is a promising new approach to reducing iron deficiency because FePO 4 NPs combine high bioavailability with superior sensory performance in difficult to fortify foods. However, their safety remains largely untested. We fed rats for 90 days diets containing FePO 4 NPs at doses at which iron sulfate (FeSO 4 ), a commonly used food fortificant, has been shown to induce adverse effects. Feeding did not result in signs of toxicity, including oxidative stress, organ damage, excess iron accumulation in organs or histological changes. These safety data were corroborated by evidence that NPs were taken up by human gastrointestinal cell lines without reducing cell viability or inducing oxidative stress. Our findings suggest FePO 4 NPs appear to be as safe for ingestion as FeSO 4 .

  3. Molecular evidence and physiological characterization of iron absorption in isolated enterocytes of rainbow trout (Oncorhynchus mykiss): Implications for dietary cadmium and lead absorption

    International Nuclear Information System (INIS)

    Kwong, Raymond W.M.; Andres, Jose A.; Niyogi, Som

    2010-01-01

    Recent studies suggested the probable involvement of an apical iron (Fe 2+ ) transporter, the divalent metal transporter-1 (DMT1), in the uptake of several divalent metals in fish. The present study examined the gastrointestinal expression of the DMT1 gene, and investigated the kinetics of Fe 2+ uptake and its interactions with cadmium and lead in isolated enterocytes of freshwater rainbow trout (Oncorhynchus mykiss). The expressions of two DMT1 isoforms (Nramp-β and -γ) were recorded along the entire gastrointestinal tract of fish as well as in the enterocytes. Fe 2+ uptake in isolated enterocytes was saturable and sensitive to the proton gradient and membrane potential, suggesting DMT1-mediated transport. Both cadmium and lead inhibited Fe 2+ uptake in isolated enterocytes in a concentration-dependent manner, and lead appeared to be a stronger inhibitor than cadmium. The kinetic characterization of Fe 2+ uptake revealed that the apparent affinity of uptake was significantly decreased (increased K m ) in the presence of either cadmium or lead, whereas the maximum uptake rate (J max ) remained unchanged-indicating that the interaction between Fe 2+ and cadmium or lead is competitive in nature. Overall, our study suggests that the uptake of dietary cadmium and lead may occur via the iron-transporting pathway in fish.

  4. Molecular evidence and physiological characterization of iron absorption in isolated enterocytes of rainbow trout (Oncorhynchus mykiss): Implications for dietary cadmium and lead absorption

    Energy Technology Data Exchange (ETDEWEB)

    Kwong, Raymond W.M. [Toxicology Centre, University of Saskatchewan, Saskatoon, SK., S7N 5B3 (Canada); Andres, Jose A. [Department of Biology, University of Saskatchewan, Saskatoon, SK., S7N 5E2 (Canada); Niyogi, Som, E-mail: som.niyogi@usask.ca [Department of Biology, University of Saskatchewan, Saskatoon, SK., S7N 5E2 (Canada)

    2010-09-01

    Recent studies suggested the probable involvement of an apical iron (Fe{sup 2+}) transporter, the divalent metal transporter-1 (DMT1), in the uptake of several divalent metals in fish. The present study examined the gastrointestinal expression of the DMT1 gene, and investigated the kinetics of Fe{sup 2+} uptake and its interactions with cadmium and lead in isolated enterocytes of freshwater rainbow trout (Oncorhynchus mykiss). The expressions of two DMT1 isoforms (Nramp-{beta} and -{gamma}) were recorded along the entire gastrointestinal tract of fish as well as in the enterocytes. Fe{sup 2+} uptake in isolated enterocytes was saturable and sensitive to the proton gradient and membrane potential, suggesting DMT1-mediated transport. Both cadmium and lead inhibited Fe{sup 2+} uptake in isolated enterocytes in a concentration-dependent manner, and lead appeared to be a stronger inhibitor than cadmium. The kinetic characterization of Fe{sup 2+} uptake revealed that the apparent affinity of uptake was significantly decreased (increased K{sub m}) in the presence of either cadmium or lead, whereas the maximum uptake rate (J{sub max}) remained unchanged-indicating that the interaction between Fe{sup 2+} and cadmium or lead is competitive in nature. Overall, our study suggests that the uptake of dietary cadmium and lead may occur via the iron-transporting pathway in fish.

  5. [Determination of trace cobalt in human urine by graphite furnace atomic absorption spectrometr].

    Science.gov (United States)

    Zhong, L X; Ding, B M; Jiang, D; Liu, D Y; Yu, B; Zhu, B L; Ding, L

    2016-05-20

    To establish a method to determine cobalt in human urine by graphite furnace atomic absorption spectrometry. Urine with 2% nitric acid diluted two-fold, to quantify the curve, graphite furnace atomic absorption spectrometric detection. Co was linear within 2.5~40.0 ng/ml with r>0.999. Spike experiment showed that Co received good recovery rate, which was 90.8%~94.8%. Intra-assay precisions were 3.2%~5.1% for Co, inter-assay precisions were 4.4%~5.2% for Co. The method by using graphite furnace atomic absorption spectrometr to determine urine Co was fast, accurate and with low matrix effect. It could meet the requirement in GBZ/T 210.5-2008.

  6. Absorption of human skin and its detecting platform in the process of laser cosmetology

    Science.gov (United States)

    Zhang, Yong-Lin; Ouyang, Li; Wang, Yang

    2000-10-01

    Because of the melanin, hemoglobin and water molecules, etc. contained, light absorption of human skin tissue changes with wavelength of light. This is the principle used in laser cosmetology for treating pigment diseases and vascular lesion diseases as well as skin decoration such as body tattooing, eyebrow tattooing, etc. The parameters of treatment used in laser cosmetology principally come from the research of the skin tissue optical characteristics of whites, and it is not suitable for the Oriental. The absorption spectrum of yellow race alive skin has been researched. The detecting platform for use in the measuring of vivi-tissue absorption spectrum has been developed which using opto-electronic nondestructive testing and virtual instrument techniques. The degree of pathological changes of skin can be detected by this platform also, thus the shortcoming of dosage selection in laser clinical treatments which have been decided only by naked eye observation and past experience of doctors can be solved.

  7. The effect of administration of copper nanoparticles to chickens in drinking water on estimated intestinal absorption of iron, zinc, and calcium.

    Science.gov (United States)

    Ognik, Katarzyna; Stępniowska, Anna; Cholewińska, Ewelina; Kozłowski, Krzysztof

    2016-09-01

    Copper nanoparticles used as a dietary supplement for poultry could affect the absorption of mineral elements. Hence the aim of the study was to determine the effect of administration of copper nanoparticles to chickens in drinking water on intestinal absorption of iron, zinc, and calcium. The experiment was carried out on 126 chicks assigned to seven experimental groups of 18 birds each (3 replications of 6 individuals each). The control group (G-C) did not receive copper nanoparticles. Groups: Cu-5(7), Cu-10(7), and Cu-15(7) received gold nanoparticles in their drinking water in the amounts of 5 mg/L for group Cu-5(7), 10 mg/L for group Cu-10(7), and 15 mg/L for group Cu-15(7) during 8 to 14, 22 to 28, and 36 of 42 days of the life of the chicks. The birds in groups Cu-5(3), Cu-10(3), and Cu-15(3) received copper nanoparticles in the same amounts, but only during 8 to 10, 22 to 24, and 36 to 38 days of life. Blood for analysis was collected from the wing vein of all chicks at the age of 42 days. After the rearing period (day 42), six birds from each experimental group with body weight similar to the group average were slaughtered. The carcasses were dissected and samples of the jejunum were collected for analysis of absorption of selected minerals. Mineral absorption was tested using the in vitro gastrointestinal sac technique. Oral administration of copper nanoparticles to chickens in the amount of 5, 10, and 15 mg/L led to accumulation of this element in the intestinal walls. The highest level of copper nanoparticles applied increased Cu content in the blood plasma of the birds. The in vitro study suggests that copper accumulated in the intestines reduces absorption of calcium and zinc, but does not affect iron absorption. © 2016 Poultry Science Association Inc.

  8. In vivo percutaneous absorption of boric acid, borax, and disodium octaborate tetrahydrate in humans compared to in vitro absorption in human skin from infinite and finite doses.

    Science.gov (United States)

    Wester, R C; Hui, X; Hartway, T; Maibach, H I; Bell, K; Schell, M J; Northington, D J; Strong, P; Culver, B D

    1998-09-01

    Literature from the first half of this century report concern for toxicity from topical use of boric acid, but assessment of percutaneous absorption has been impaired by lack of analytical sensitivity. Analytical methods in this study included inductively coupled plasma-mass spectrometry which now allows quantitation of percutaneous absorption of 10B in 10B-enriched boric acid, borax, and disodium octaborate tetrahydrate (DOT) in biological matrices. This made it possible, in the presence of comparatively large natural dietary boron intakes for the in vivo segment of this study, to quantify the boron passing through skin. Human volunteers were dosed with 10B-enriched boric acid, 5.0%, borax, 5.0%, or disodium octaborate tetrahydrate, 10%, in aqueous solutions. Urinalysis, for boron and changes in boron isotope ratios, was used to measure absorption. Boric acid in vivo percutaneous absorption was 0.226 (SD = 0.125) mean percentage dose, with flux and permeability constant (Kp) calculated at 0.009 microgram/cm2/h and 1.9 x 10(-7) cm/h, respectively. Borax absorption was 0.210 (SD = 0.194) mean percentage of dose, with flux and Kp calculated at 0.009 microgram/cm2/h and 1.8 x 10(-7) cm/h, respectively. DOT absorption was 0.122 (SD = 0.108) mean percentage, with flux and Kp calculated at 0.01 microgram/cm2/h and 1.0 x 10(-7) cm/h, respectively. Pretreatment with the potential skin irritant 2% sodium lauryl sulfate had no effect on boron skin absorption. In vitro human skin percentage of doses of boric acid absorbed were 1.2 for a 0.05% solution, 0.28 for a 0.5% solution, and 0.70 for a 5.0% solution. These absorption amounts translated into flux values of, respectively, 0.25, 0.58, and 14.58 micrograms/cm2/h and permeability constants (Kp) of 5.0 x 10(-4), 1.2 x 10(-4), and 2.9 x 10(-4) cm/h for the 0.05, 0.5, and 5.0% solutions. The above in vitro doses were at infinite, 1000 microliters/cm2 volume. At 2 microliters/cm2 (the in vivo dosing volume), flux decreased some

  9. Correlation between oral drug absorption in humans and apparent drug permeability coefficients in human intestinal epithelial (Caco-2) cells

    International Nuclear Information System (INIS)

    Artursson, P.; Karlsson, J.

    1991-01-01

    Monolayers of a well differentiated human intestinal epithelial cell line, Caco-2, were used as a model to study passive drug absorption across the intestinal epithelium. Absorption rate constants (expressed as apparent permeability coefficients) were determined for 20 drugs and peptides with different structural properties. The permeability coefficients ranged from approximately 5 x 10 - 8 to 5 x 10 - 5 cm/s. A good correlation was obtained between data on oral absorption in humans and the results in the Caco-2 model. Drugs that are completely absorbed in humans had permeability coefficients greater than 1 x 10 - 6 cm/s. Drugs that are absorbed to greater than 1% but less than 100% had permeability coefficients of 0.1-1.0 x 10 - 6 cm/s while drugs and peptides that are absorbed to less than 1% had permeability coefficients of less than or equal to 1 x 10 - 7 cm/s. The results indicate that Caco-2 monolayers can be used as a model for studies on intestinal drug absorption

  10. Effect of iron oxide reductive dissolution on the transformation and immobilization of arsenic in soils: New insights from X-ray photoelectron and X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Jian-Xin [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing 400074 (China); Wang, Yu-Jun, E-mail: yjwang@issas.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Liu, Cun [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Wang, Li-Hua; Yang, Ke [Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of sciences, Shanghai 201204 (China); Zhou, Dong-Mei, E-mail: dmzhou@issas.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Li, Wei; Sparks, Donald L. [Environmental Soil Chemistry Group, Delaware Environmental Institute and Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19717-1303 United States (United States)

    2014-08-30

    Graphical abstract: - Highlights: • Immobility and transformation of As on different Eh soils were investigated. • μ-XRF, XANES, and XPS were used to gain As distribution and speciation in soil. • Sorption capacity of As on anaerobic soil was much higher than that on oxic soil. • Fe oxides reductive dissolution is a key factor for As sorption and transformation. - Abstract: The geochemical behavior and speciation of arsenic (As) in paddy soils is strongly controlled by soil redox conditions and the sequestration by soil iron oxyhydroxides. Hence, the effects of iron oxide reductive dissolution on the adsorption, transformation and precipitation of As(III) and As(V) in soils were investigated using batch experiments and synchrotron based techniques to gain a deeper understanding at both macroscopic and microscopic scales. The results of batch sorption experiments revealed that the sorption capacity of As(V) on anoxic soil was much higher than that on control soil. Synchrotron based X-ray fluorescence (μ-XRF) mapping studies indicated that As was heterogeneously distributed and was mainly associated with iron in the soil. X-ray absorption near edge structure (XANES), micro-X-ray absorption near edge structure (μ-XANES) and X-ray photoelectron spectroscopy (XPS) analyses revealed that the primary speciation of As in the soil is As(V). These results further suggested that, when As(V) was introduced into the anoxic soil, the rapid coprecipitation of As(V) with ferric/ferrous ion prevented its reduction to As(III), and was the main mechanism controlling the immobilization of As. This research could improve the current understanding of soil As chemistry in paddy and wetland soils.

  11. Effect of iron oxide reductive dissolution on the transformation and immobilization of arsenic in soils: New insights from X-ray photoelectron and X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Fan, Jian-Xin; Wang, Yu-Jun; Liu, Cun; Wang, Li-Hua; Yang, Ke; Zhou, Dong-Mei; Li, Wei; Sparks, Donald L.

    2014-01-01

    Graphical abstract: - Highlights: • Immobility and transformation of As on different Eh soils were investigated. • μ-XRF, XANES, and XPS were used to gain As distribution and speciation in soil. • Sorption capacity of As on anaerobic soil was much higher than that on oxic soil. • Fe oxides reductive dissolution is a key factor for As sorption and transformation. - Abstract: The geochemical behavior and speciation of arsenic (As) in paddy soils is strongly controlled by soil redox conditions and the sequestration by soil iron oxyhydroxides. Hence, the effects of iron oxide reductive dissolution on the adsorption, transformation and precipitation of As(III) and As(V) in soils were investigated using batch experiments and synchrotron based techniques to gain a deeper understanding at both macroscopic and microscopic scales. The results of batch sorption experiments revealed that the sorption capacity of As(V) on anoxic soil was much higher than that on control soil. Synchrotron based X-ray fluorescence (μ-XRF) mapping studies indicated that As was heterogeneously distributed and was mainly associated with iron in the soil. X-ray absorption near edge structure (XANES), micro-X-ray absorption near edge structure (μ-XANES) and X-ray photoelectron spectroscopy (XPS) analyses revealed that the primary speciation of As in the soil is As(V). These results further suggested that, when As(V) was introduced into the anoxic soil, the rapid coprecipitation of As(V) with ferric/ferrous ion prevented its reduction to As(III), and was the main mechanism controlling the immobilization of As. This research could improve the current understanding of soil As chemistry in paddy and wetland soils

  12. Calculation of optical and K pre-edge absorption spectra for ferrous iron of distorted sites in oxide crystals

    Science.gov (United States)

    Vercamer, Vincent; Hunault, Myrtille O. J. Y.; Lelong, Gérald; Haverkort, Maurits W.; Calas, Georges; Arai, Yusuke; Hijiya, Hiroyuki; Paulatto, Lorenzo; Brouder, Christian; Arrio, Marie-Anne; Juhin, Amélie

    2016-12-01

    Advanced semiempirical calculations have been performed to compute simultaneously optical absorption and K pre-edge x-ray absorption spectra of Fe2 + in four distinct site symmetries found in minerals. The four symmetries, i.e., a distorted octahedron, a distorted tetrahedron, a square planar site, and a trigonal bipyramidal site, are representative of the Fe2 + sites found in crystals and glasses. A particular attention has been paid to the definition of the p -d hybridization Hamiltonian which occurs for noncentrosymmetric symmetries in order to account for electric dipole transitions. For the different sites under study, an excellent agreement between calculations and experiments was found for both optical and x-ray absorption spectra, in particular in terms of relative intensities and energy positions of electronic transitions. To our knowledge, these are the first calculations of optical absorption spectra on Fe2 + placed in such diverse site symmetries, including centrosymmetric sites. The proposed theoretical model should help to interpret the features of both the optical absorption and the K pre-edge absorption spectra of 3 d transition metal ions and to go beyond the usual fingerprint interpretation.

  13. Isotope-aided studies of the bioavailability of iron and zinc from human diets consumed in Poland

    International Nuclear Information System (INIS)

    Rafalski, H.; Switoniak, T.

    1994-01-01

    The bioavailability of food iron is affected by a number of physiological and dietary variables and it should be checked for the population living in natural conditions. The primary purpose of this study was to measure in volunteers iron absorption after oral administration of a wheat roll enriched with 15 mg of Fe as FeSO 4· 7H 2 O and 20 μCi of 59 Fe. For assessment of iron absorption whole body counting was used. The secondary purpose was to relate the available iron to iron stores, anthropometric indices, bleeding days and dietary variables. Thirteen female and 7 male healthy subjects aged between 19 and 47 years were observed. Hematological measurements on blood: serum ferritin (SF), serum iron (SI), total iron binding capacity (TIBC), transferrin (ST), transferrin saturation (TS), hemoglobin (Hb), hematocrit (Hct), red blood cell (RBC), mean corpuscular volume (MCV) were made. The subjects were examined by a specialist in internal medicine. Their 24-hour recall food intake was performed by questionnaire. The findings concerning the purposes of the study may be summarized as follows: 1) mean absorbed iron was 1.6 ± 1.2 mg for women, and 0.5±0.2 mg for men; 2) iron stores evaluated from SF were in women 2.6± 1.7 mg/kg body weight and in men 10.4±5.4 mg/kg; 3) blood indices proved iron deficiency anemia in 1 woman, Hb = 9.2 g/dL, SF = 1.8 μg/L, TS = 6%; in 4 women deficient iron stores were observed, Hb > 12g/dL, SF < 12 mg/L; 8 women and 7 men were normal; 4) in women the absorbed iron related inversely to SF (-0.61) and iron stores (-0.61); 5) the iron stores related to the sum of four skinfolds in women (0.55) and in men (0.80), in women it related to body weight (0.77) too; 6) in women the absorbed iron related to bleeding days (0.69); 7) in women ascorbic acid consumption related to iron store indices; SF, SI and TS. (author). 2 figs, 3 tabs

  14. Dynamics of absorption, metabolism, and excretion of 5-aminolevulinic acid in human intestinal Caco-2 cells

    Directory of Open Access Journals (Sweden)

    Kei Saito

    2017-09-01

    Full Text Available 5-Aminolevulinic acid (ALA is a precursor for the biosynthesis of porphyrins and heme. Although the oral administration of ALA has been widely applied in clinical settings, the dynamics of its absorption, metabolism, and excretion within enterocytes remain unknown. In this study, after enterocytic differentiation, Caco-2 cells were incubated with 200 µM ALA and/or 100 µM sodium ferrous citrate (SFC for up to 72 h. Both ALA and the combination of ALA and SFC promoted the synthesis of heme, without affecting the expression of genes involved in intestinal iron transport, such as DMT1 and FPN. The enhanced heme synthesis in Caco-2 cells was more pronounced under the effect of the combination of ALA and SFC than under the effect of ALA alone, as reflected by the induced expression of heme oxygenase 1 (HO-1, as well as a reduced protein level of the transcriptional corepressor Bach1. Chromatin immunoprecipitation analysis confirmed Bach1 chromatin occupancy at the enhancer regions of HO-1, which were significantly decreased by the addition of ALA and SFC. Finally, Transwell culture of Caco-2 cells suggested that the administered ALA to the intestinal lumen was partially transported into vasolateral space. These findings enhance our understanding of the absorption and metabolism of ALA in enterocytes, which could aid in the development of a treatment strategy for various conditions such as anemia.

  15. Oral absorption of peptides and nanoparticles across the human intestine: Opportunities, limitations and studies in human tissues.

    Science.gov (United States)

    Lundquist, P; Artursson, P

    2016-11-15

    In this contribution, we review the molecular and physiological barriers to oral delivery of peptides and nanoparticles. We discuss the opportunities and predictivity of various in vitro systems with special emphasis on human intestine in Ussing chambers. First, the molecular constraints to peptide absorption are discussed. Then the physiological barriers to peptide delivery are examined. These include the gastric and intestinal environment, the mucus barrier, tight junctions between epithelial cells, the enterocytes of the intestinal epithelium, and the subepithelial tissue. Recent data from human proteome studies are used to provide information about the protein expression profiles of the different physiological barriers to peptide and nanoparticle absorption. Strategies that have been employed to increase peptide absorption across each of the barriers are discussed. Special consideration is given to attempts at utilizing endogenous transcytotic pathways. To reliably translate in vitro data on peptide or nanoparticle permeability to the in vivo situation in a human subject, the in vitro experimental system needs to realistically capture the central aspects of the mentioned barriers. Therefore, characteristics of common in vitro cell culture systems are discussed and compared to those of human intestinal tissues. Attempts to use the cell and tissue models for in vitro-in vivo extrapolation are reviewed. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  16. Direct microcomputer controlled determination of zinc in human serum by flow injection atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Simonsen, Kirsten Wiese; Nielsen, Bent; Jensen, Arne

    1986-01-01

    A procedure is described for the direct determination of zinc in human serum by fully automated, microcomputer controlled flow injection atomic absorption spectrometry (Fl-AAS). The Fl system is pumpless, using the negative pressure created by the nebuliser. It only consists of a three-way valve......, programmable from the microcomputer, to control the sample volume. No pre-treatment of the samples is necessary. The limit of detection is 0.14 mg l–1, and only small amounts of serum (

  17. Consensus hologram QSAR modeling for the prediction of human intestinal absorption.

    Science.gov (United States)

    Moda, Tiago L; Andricopulo, Adriano D

    2012-04-15

    Consistent in silico models for ADME properties are useful tools in early drug discovery. Here, we report the hologram QSAR modeling of human intestinal absorption using a dataset of 638 compounds with experimental data associated. The final validated models are consistent and robust for the consensus prediction of this important pharmacokinetic property and are suitable for virtual screening applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Differences in iron acquisition from human haemoglobin among strains of Actinobacillus actinomycetemcomitans

    DEFF Research Database (Denmark)

    Hayashida, H.; Poulsen, Knud; Kilian, Mogens

    2002-01-01

    . actinomycetemcomitans strains examined harboured a single genomic sequence with homology to the hgpA gene encoding haemoglobin-binding protein A in Haemophilus influenzae. However, in all three strains belonging to the JP2 clone and in one serotype e strain hgpA was a pseudogene. Seven other strains possessed...... a functional hgpA gene which, according to insertion mutagenesis experiments, was responsible for the ability of these strains to utilize haemoglobin as a source of iron. Thus, the presence of an hgpA pseudogene and the inability to use human haemoglobin as an iron source discriminate the high-toxic JP2 clone...

  19. Severe iron deficiency anemia and marked eosinophilia in adolescent girls with the diagnosis of human fascioliasis.

    Science.gov (United States)

    Tavil, Betül; Ok-Bozkaya, İkbal; Tezer, Hasan; Tunç, Bahattin

    2014-01-01

    Human fascioliasis (HF), caused by the common liver fluke Fasciola hepatica, is an endemic infection in many parts of tropical countries. HF can also be seen in some of the non-tropical countries. This report describes two girls with severe iron deficiency anemia and eosinophilia, who were diagnosed as HF. The infection was successfully eliminated with the administration of triclabendazole. No side effects or recurrence was observed after the treatment. It should be kept in mind that marked eosinophilia with severe iron deficiency anemia should alert pediatricians to the possibility of F. hepatica infection.

  20. In vivo determination of the absorption and scattering spectra of the human prostate during photodynamic therapy

    Science.gov (United States)

    Finlay, Jarod C.; Zhu, Timothy C.; Dimofte, Andreea; Stripp, Diana C. H.; Malkowicz, S. B.; Whittington, Richard; Miles, Jeremy; Glatstein, Eli; Hahn, Stephen M.

    2004-06-01

    A continuing challenge in photodynamic therapy is the accurate in vivo determination of the optical properties of the tissue being treated. We have developed a method for characterizing the absorption and scattering spectra of prostate tissue undergoing PDT treatment. Our current prostate treatment protocol involves interstitial illumination of the organ via cylindrical diffusing optical fibers (CDFs) inserted into the prostate through clear catheters. We employ one of these catheters to insert an isotropic white light point source into the prostate. An isotropic detection fiber connected to a spectrograph is inserted into a second catheter a known distance away. The detector is moved along the catheter by a computer-controlled step motor, acquiring diffuse light spectra at 2 mm intervals along its path. We model the fluence rate as a function of wavelength and distance along the detector"s path using an infinite medium diffusion theory model whose free parameters are the absorption coefficient μa at each wavelength and two variables A and b which characterize the reduced scattering spectrum of the form μ"s = Aλ-b. We analyze our spectroscopic data using a nonlinear fitting algorithm to determine A, b, and μa at each wavelength independently; no prior knowledge of the absorption spectrum or of the sample"s constituent absorbers is required. We have tested this method in tissue simulating phantoms composed of intralipid and the photosensitizer motexafin lutetium (MLu). The MLu absorption spectrum recovered from the phantoms agrees with that measured in clear solution, and μa at the MLu absorption peak varies linearly with concentration. The ´"s spectrum reported by the fit is in agreement with the known scattering coefficient of intralipid. We have applied this algorithm to spectroscopic data from human patients sensitized with MLu (2 mg kg-1) acquired before and after PDT. Before PDT, the absorption spectra we measure include the characteristic MLu absorption

  1. Review: The Potential of the Common Bean (Phaseolus vulgaris as a Vehicle for Iron Biofortification

    Directory of Open Access Journals (Sweden)

    Nicolai Petry

    2015-02-01

    Full Text Available Common beans are a staple food and the major source of iron for populations in Eastern Africa and Latin America. Bean iron concentration is high and can be further increased by biofortification. A major constraint to bean iron biofortification is low iron absorption, attributed to inhibitory compounds such as phytic acid (PA and polyphenol(s (PP. We have evaluated the usefulness of the common bean as a vehicle for iron biofortification. High iron concentrations and wide genetic variability have enabled plant breeders to develop high iron bean varieties (up to 10 mg/100 g. PA concentrations in beans are high and tend to increase with iron biofortification. Short-term human isotope studies indicate that iron absorption from beans is low, PA is the major inhibitor, and bean PP play a minor role. Multiple composite meal studies indicate that decreasing the PA level in the biofortified varieties substantially increases iron absorption. Fractional iron absorption from composite meals was 4%–7% in iron deficient women; thus the consumption of 100 g biofortified beans/day would provide about 30%–50% of their daily iron requirement. Beans are a good vehicle for iron biofortification, and regular high consumption would be expected to help combat iron deficiency (ID.

  2. Nutritional iron deficiency

    NARCIS (Netherlands)

    Zimmermann, M.B.; Hurrell, R.F.

    2007-01-01

    Iron deficiency is one of the leading risk factors for disability and death worldwide, affecting an estimated 2 billion people. Nutritional iron deficiency arises when physiological requirements cannot be met by iron absorption from diet. Dietary iron bioavailability is low in populations consuming

  3. Effect of nickel and iron co-exposure on human lung cells

    International Nuclear Information System (INIS)

    Salnikow, Konstantin; Li Xiaomei; Lippmann, Morton

    2004-01-01

    Exposure to ambient air particulate matter (PM) is associated with increased mortality and morbidity in susceptible populations. The epidemiological data also suggest a relationship between PM air pollution and impairment of cardiopulmonary function. The mechanisms that may be responsible for these effects are not fully understood and are likely related to perturbations of cellular and molecular functions. One type of PM, residual oil fly ash (ROFA), is of particular interest. ROFA does not contain much organic material, but does contain relatively high quantities of transition metals, predominantly nickel, vanadium, and iron, as well as black carbon and sulfates. In this study, we investigated the effect of two metals (iron and nickel) on the induction of 'hypoxia-like' stress and the production of interleukins (ILs) in minimally transformed human airway epithelial cells (1HAEo - ). We found that exposure to soluble nickel sulfate results in the induction of hypoxia-inducible genes and IL-8 production by the 1HAEo - cells. The simultaneous addition of iron in either ferric or ferrous form and nickel completely inhibited IL-8 production and had no effect on 'hypoxia-like' stress caused by nickel, suggesting the existence of two different pathways for the induction 'hypoxia-like' stress and IL-8 production. The effect of nickel was not related to the blocking of iron entry into cells since the level of intracellular iron was not affected by co-exposure with nickel. The obtained data indicate that nickel can induce different signaling pathways with or without interference with iron metabolism. Our observations suggest that in some cases the excess of iron in PM can cancel the effects of nickel

  4. [Iron nutrition in Mapuche infants fed with human milk (2d phase)].

    Science.gov (United States)

    Franco, E; Hertrampf, E; Rodríguez, E; Illanes, J C; Palacios, L; Llaguno, S; Lettelier, A

    1990-01-01

    Blood hemoglobin, serum iron, total iron binding capacity (TIBC) and serum ferritin were measured in 140 healthy rural mapuche (southern Chile's indigenous ethnic group) infants aged 8 to 15 months: 90 had been exclusively breast fed for the first 5 or 6 months of life, then solid foods were introduced but cow's milk was never given to them. The remaining 50, which were all weaned at nearly 4 months of age and then given cow's milk and solid foods at the corresponding age, were designated as controls. Anemia was detected in 4.5% of breast fed infants and in 38% of controls. Evidence of iron deficient erythropoiesis was found in 5% and 81% of cases and controls, respectively. Human milk apparently protects this ethnic group from iron deficiency anemia and this protection seems to be better in mapuche infants than in other groups of chilean infants, because these late have shown 30% incidence of anemia around the first year of life in other studies. More studies on differences in iron nutritional state among mapuche and non mapuche are needed and are under way.

  5. The distribution of iron between the metal-binding sites of transferrin human serum.

    Science.gov (United States)

    Williams, J; Moreton, K

    1980-02-01

    The Makey & Seal [(1976) Biochim. Biophys. Acta 453, 250--256] method of polyacrylamide-gel electrophoresis in buffer containing 6 M-urea was used to determine the distribution of iron between the N-terminal and C-terminal iron-binding sites of transferrin in human serum. In fresh serum the two sites are unequally occupied; there is preferential occupation of the N-terminal site. On incubation of the serum at 37 degrees C the preference of iron for the N-terminal site becomes more marked. On storage of serum at -15 degrees C the iron distribution changes so that there is a marked preference for the C-terminal site. Dialysis of serum against buffer at pH 7.4 also causes iron to be bound much more strongly by the C-terminal than by the N-terminal site. The original preference for the N-terminal site can be resroted to the dialysed serum by addition of the diffusible fraction.

  6. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... an MCV of less than 80 femtoliters (fL). Prevention strategies If you have certain risk factors , such ... drinking black tea, which reduces iron absorption. Other treatments If you have chronic kidney disease and iron- ...

  7. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... C to help your body absorb iron. Avoid drinking black tea, which reduces iron absorption. Other treatments ... improve health through research and scientific discovery. Improving health with current research Learn about the following ways ...

  8. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... also often take other medicines—such as proton pump inhibitors, anticoagulants, or blood thinners—that may cause iron-deficiency anemia. Proton pump inhibitors interfere with iron absorption, and blood thinners ...

  9. Study to determine the content of vanadium, aluminum, nickel, sodium, iron and copper in a catalytic cracking catalyst, by using Atomic Absorption Spectrometry

    International Nuclear Information System (INIS)

    Gomez, J.; Alonso, A.; Tumbarell, O.; Bustanmete, E.

    2003-01-01

    Atomic Absorption Spectrometry (AAS), has the advantage of its simplicity, speed and low cost. All this, together with its high sensibility and selectivity, makes the AAS one the most widely used analytic techniques. The present work shows, the study to determine the content of vanadium, aluminum, nickel, sodium, iron and copper in a catalytic cracking catalyst of a refinery, by using this technique. The results are compared to those of two laboratories which use the ICP-AES and AAS techniques and shows the processing of the statistics with the use of the t of Student and the F of Snedecor. The results using different methods are also shown as well as the recommended application of this results in the chemical characterization of this type of catalysts

  10. In Silico Prediction for Intestinal Absorption and Brain Penetration of Chemical Pesticides in Humans.

    Science.gov (United States)

    Chedik, Lisa; Mias-Lucquin, Dominique; Bruyere, Arnaud; Fardel, Olivier

    2017-06-30

    Intestinal absorption and brain permeation constitute key parameters of toxicokinetics for pesticides, conditioning their toxicity, including neurotoxicity. However, they remain poorly characterized in humans. The present study was therefore designed to evaluate human intestine and brain permeation for a large set of pesticides ( n = 338) belonging to various chemical classes, using an in silico graphical BOILED-Egg/SwissADME online method based on lipophilicity and polarity that was initially developed for drugs. A high percentage of the pesticides (81.4%) was predicted to exhibit high intestinal absorption, with a high accuracy (96%), whereas a lower, but substantial, percentage (38.5%) displayed brain permeation. Among the pesticide classes, organochlorines ( n = 30) constitute the class with the lowest percentage of intestine-permeant members (40%), whereas that of the organophosphorus compounds ( n = 99) has the lowest percentage of brain-permeant chemicals (9%). The predictions of the permeations for the pesticides were additionally shown to be significantly associated with various molecular descriptors well-known to discriminate between permeant and non-permeant drugs. Overall, our in silico data suggest that human exposure to pesticides through the oral way is likely to result in an intake of these dietary contaminants for most of them and brain permeation for some of them, thus supporting the idea that they have toxic effects on human health, including neurotoxic effects.

  11. Estimation of perimortal percent carboxy-heme in nonstandard postmortem specimens using analysis of carbon monoxide by GC/MS and iron by flame atomic absorption spectrophotometry.

    Science.gov (United States)

    Middleberg, R A; Easterling, D E; Zelonis, S F; Rieders, F; Rieders, M F

    1993-01-01

    In decomposed, formalin-fixed, embalmed, exhumed, and some fire-dried cases in which normal blood is unavailable, the usual methods for determination of carboxyhemoglobin saturation frequently fail. To address these specimens, a method utilizing both gas chromatography/mass spectrometric (GC/MS) determination of carbon monoxide (CO) and flame atomic absorption spectrophotometry (FAAS) determination of iron (Fe), in the same specimen, was developed. The method is reported here, along with its application to seven pertinent forsensic death investigations. The CO analytical methodology involves acid liberation of the gas from the specimen aliquot in a headspace vial. After heating and equilibrating, a sample of the headspace vapor is injected into the GC/MS system with a gastight syringe. Quantitation is achieved by standard addition comparison utilizing the ideal gas law equation. Iron is quantified by FAAS analysis of the same aliquot used for the CO determination, following nitric acid digestion. The concentration is determined by comparison to a standard curve. A formula for determining the minimum percent carboxy-heme saturation was derived by using the ratio of the amount of CO to the amount of Fe in the aliquot analyzed. Tissue types analyzed include spleen, liver, muscle, dried blood, and unspecified decomposed tissue.

  12. Facile synthesis of iron oxides/reduced graphene oxide composites: application for electromagnetic wave absorption at high temperature

    OpenAIRE

    Lili Zhang; Xinxin Yu; Hongrui Hu; Yang Li; Mingzai Wu; Zhongzhu Wang; Guang Li; Zhaoqi Sun; Changle Chen

    2015-01-01

    Iron oxides/reduced graphene oxide composites were synthesized by facile thermochemical reactions of graphite oxide and FeSO4?7H2O. By adjusting reaction temperature, ?-Fe2O3/reduced graphene oxide and Fe3O4/reduced graphene oxide composites can be obtained conveniently. Graphene oxide and reduced graphene oxide sheets were demonstrated to regulate the phase transition from ?-Fe2O3 to Fe3O4 via ?-Fe2O3, which was reported for the first time. The hydroxyl groups attached on the graphene oxide ...

  13. The Capacity of Mycobacterium tuberculosis To Survive Iron Starvation Might Enable It To Persist in Iron-Deprived Microenvironments of Human Granulomas.

    Science.gov (United States)

    Kurthkoti, Krishna; Amin, Hamel; Marakalala, Mohlopheni J; Ghanny, Saleena; Subbian, Selvakumar; Sakatos, Alexandra; Livny, Jonathan; Fortune, Sarah M; Berney, Michael; Rodriguez, G Marcela

    2017-08-15

    This study was conducted to investigate the role of iron deprivation in the persistence of Mycobacterium tuberculosis We present evidence of iron restriction in human necrotic granulomas and demonstrate that under iron starvation M. tuberculosis persists, refractive to antibiotics and capable of restarting replication when iron is made available. Transcriptomics and metabolomic analyses indicated that the persistence of M. tuberculosis under iron starvation is dependent on strict control of endogenous Fe utilization and is associated with upregulation of pathogenicity and intrinsic antibiotic resistance determinants. M. tuberculosis mutants compromised in their ability to survive Fe starvation were identified. The findings of this study advance the understanding of the physiological settings that may underpin the chronicity of human tuberculosis (TB) and are relevant to the design of effective antitubercular therapies. IMPORTANCE One-third of the world population may harbor persistent M. tuberculosis , causing an asymptomatic infection that is refractory to treatment and can reactivate to become potentially lethal tuberculosis disease. However, little is known about the factors that trigger and maintain M. tuberculosis persistence in infected individuals. Iron is an essential nutrient for M. tuberculosis growth. In this study, we show, first, that in human granulomas the immune defense creates microenvironments in which M. tuberculosis likely experiences drastic Fe deprivation and, second, that Fe-starved M. tuberculosis is capable of long-term persistence without growth. Together, these observations suggest that Fe deprivation in the lung might trigger a state of persistence in M. tuberculosis and promote chronic TB. We also identified vulnerabilities of iron-restricted persistent M. tuberculosis , which can be exploited for the design of new antitubercular therapies. Copyright © 2017 Kurthkoti et al.

  14. Low-field microwave absorption and magnetoresistance in iron nanostructures grown by electrodeposition on n-type lightly doped silicon substrates

    Energy Technology Data Exchange (ETDEWEB)

    Felix, J.F. [Universidade Federal de Viçosa-UFV, Departamento de Física, 36570-900 Viçosa, MG (Brazil); Universidade de Brasília-UnB, Instituto de Física, Núcleo de Física Aplicada, 70910-900 Brasília, DF (Brazil); Figueiredo, L.C. [Universidade de Brasília-UnB, Instituto de Física, Núcleo de Física Aplicada, 70910-900 Brasília, DF (Brazil); Mendes, J.B.S. [Universidade Federal de Viçosa-UFV, Departamento de Física, 36570-900 Viçosa, MG (Brazil); Morais, P.C. [Universidade de Brasília-UnB, Instituto de Física, Núcleo de Física Aplicada, 70910-900 Brasília, DF (Brazil); Huazhong University of Science and Technology, School of Automation, 430074 Wuhan (China); Araujo, C.I.L. de., E-mail: dearaujo@ufv.br [Universidade de Brasília-UnB, Instituto de Física, Núcleo de Física Aplicada, 70910-900 Brasília, DF (Brazil)

    2015-12-01

    In this study we investigate magnetic properties, surface morphology and crystal structure in iron nanoclusters electrodeposited on lightly doped (100) n-type silicon substrates. Our goal is to investigate the spin injection and detection in the Fe/Si lateral structures. The samples obtained under electric percolation were characterized by magnetoresistive and magnetic resonance measurements with cycling the sweeping applied field in order to understand the spin dynamics in the as-produced samples. The observed hysteresis in the magnetic resonance spectra, plus the presence of a broad peak in the non-saturated regime confirming the low field microwave absorption (LFMA), were correlated to the peaks and slopes found in the magnetoresistance curves. The results suggest long range spin injection and detection in low resistive silicon and the magnetic resonance technique is herein introduced as a promising tool for analysis of electric contactless magnetoresistive samples. - Highlights: • Electrodeposition of Fe nanostructures on high resistive silicon substrates. • Spin polarized current among clusters through Si suggested by isotropic magnetoresistance. • Low field microwave absorption arising from the sample shape anisotropy. • Contactless magnetoresistive device characterization by resonance measurements.

  15. Iron overload of human colon adenocarcinoma cells studied by synchrotron-based X-ray techniques

    NARCIS (Netherlands)

    Mihucz, Victor G.; Meirer, Florian; Polgári, Zsófia; Réti, Andrea; Pepponi, Giancarlo; Ingerle, Dieter; Szoboszlai, Norbert; Streli, Christina

    2016-01-01

    Fast- and slow-proliferating human adenocarcinoma colorectal cells, HT-29 and HCA-7, respectively, overloaded with transferrin (Tf), Fe(III) citrate, Fe(III) chloride and Fe(II) sulfate were studied by synchrotron radiation total-reflection X-ray spectrometry (TXRF), TXRF-X-ray absorption near edge

  16. Dermal absorption behavior of fluorescent molecules in nanoparticles on human and porcine skin models.

    Science.gov (United States)

    Debotton, Nir; Badihi, Amit; Robinpour, Mano; Enk, Claes D; Benita, Simon

    2017-05-30

    The percutaneous passage of poorly skin absorbed molecules can be improved using nanocarriers, particularly biodegradable polymeric nanospheres (NSs) or nanocapsules (NCs). However, penetration of the encapsulated molecules may be affected by other factors than the nanocarrier properties. To gain insight information on the skin absorption of two fluorescent cargos, DiIC 18 (5) and coumarin-6 were incorporated in NSs or NCs and topically applied on various human and porcine skin samples. 3D imaging techniques suggest that NSs and NCs enhanced deep dermal penetration of both probes similarly, when applied on excised human skin irrespective of the nature of the cargo. However, when ex vivo pig skin was utilized, the cutaneous absorption of DiIC 18 (5) was more pronounced by means of PLGA NCs than NSs. In contrast, PLGA NSs noticeably improved the porcine skin penetration of coumarin-6, as compared to the NCs. Furthermore, the porcine skin results were reproducible when triplicated whereas from various human skin samples, as expected, the results were not sufficiently reproducible and large deviations were observed. The overall findings from this comprehensive comparison emphasize the potential of PLGA NCs or NSs to promote cutaneous bioavailability of encapsulated drugs, exhibiting different physicochemical properties but depending on the nature of the skin. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Determination of cobalt in human liver by atomic absorption spectrometry with electrothermal atomization

    International Nuclear Information System (INIS)

    Caldas, E.D.; Gine-Rosias, M.F.; Dorea, J.G.

    1991-01-01

    A detailed study of the use of electrothermal atomic absorption spectrometry for the determination of cobalt in human liver is described. Comparisons of sample digestion using nitric acid or nitric acid plus perchloric acid, atomization procedures and the application of palladium and magnesium nitrate chemical modifiers were studied using NBS SRM 1577a Bovine Liver. The best results were achieved with sample decomposition in nitric acid, atomization from the tube wall and no chemical modifier. Cobalt was determined in 90 samples of livers from foetuses and deceased newborns using the standard addition method with an average recovery of 99.8%. (author). 30 refs.; 4 figs.; 2 tabs

  18. Fluorophore-conjugated iron oxide nanoparticle labeling and analysis of engrafting human hematopoietic stem cells

    DEFF Research Database (Denmark)

    Maxwell, Dustin J; Bonde, Jesper; Hess, David A

    2008-01-01

    culture conditions to maintain viability without inducing terminal differentiation. In the current study, fluorescent molecules were covalently linked to dextran-coated iron oxide nanoparticles (Feridex) to characterize human HSC labeling to monitor the engraftment process. Conjugating fluorophores...... to the dextran coat for fluorescence-activated cell sorting purification eliminated spurious signals from nonsequestered nanoparticle contaminants. A short-term defined incubation strategy was developed that allowed efficient labeling of both quiescent and cycling HSC, with no discernable toxicity in vitro...

  19. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014 . Scientific Opinion on the substantiation of a health claim related to vitamin C and increasing non-haem iron absorption pursuant to Article 14 of Regulation (EC ) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    to deliver an opinion on the scientific substantiation of a health claim related to vitamin C and increasing non haem iron absorption. The food constituent, vitamin C, which is the subject of the health claim, is sufficiently characterised. Increasing non haem iron absorption is a beneficial physiological...... effect for infants and young children. A claim on vitamin C and increasing non haem iron absorption in the general population has already been assessed by the Panel with a favourable outcome. The Panel considers that the role of vitamin C in increasing non haem iron absorption applies to all ages......, including infants and young children (from birth to three years). The Panel concludes that a cause and effect relationship has been established between the dietary intake of vitamin C and increasing non haem iron absorptions....

  20. Morphologic study of the effect of iron on pseudocyst formation in Trichomonas vaginalis and its interaction with human epithelial cells.

    Science.gov (United States)

    Dias-Lopes, Geovane; Saboia-Vahia, Leonardo; Margotti, Eliane Trindade; Fernandes, Nilma de Souza; Castro, Cássia Luana de Faria; Oliveira, Francisco Odencio; Peixoto, Juliana Figueiredo; Britto, Constança; Silva, Fernando Costa E; Cuervo, Patricia; Jesus, José Batista de

    2017-10-01

    Trichomonas vaginalis is the aetiological agent of human trichomoniasis, which is one of the most prevalent sexually transmitted diseases in humans. Iron is an important element for the survival of this parasite and the colonisation of the host urogenital tract. In this study, we investigated the effects of iron on parasite proliferation in the dynamics of pseudocyst formation and morphologically characterised iron depletion-induced pseudocysts. We performed structural and ultrastructural analyses using light microscopy, scanning electron microscopy and transmission electron microscopy. It was observed that iron depletion (i) interrupts the proliferation of T. vaginalis, (ii) induces morphological changes in typical multiplicative trophozoites to spherical non-proliferative, non-motile pseudocysts, and (iii) induces the arrest of cell division at different stages of the cell cycle; (iv) iron is the fundamental element for the maintenance of typical trophozoite morphology; (v) pseudocysts induced by iron depletion are viable and reversible forms; and, finally, (vi) we demonstrated that pseudocysts induced by iron depletion are able to interact with human epithelial cells maintaining their spherical forms. Together, these data suggest that pseudocysts could be induced as a response to iron nutritional stress and could have a potential role in the transmission and infection of T. vaginalis.

  1. Hepcidin: A Critical Regulator of Iron Metabolism during Hypoxia

    Directory of Open Access Journals (Sweden)

    Korry J. Hintze

    2011-01-01

    Full Text Available Iron status affects cognitive and physical performance in humans. Recent evidence indicates that iron balance is a tightly regulated process affected by a series of factors other than diet, to include hypoxia. Hypoxia has profound effects on iron absorption and results in increased iron acquisition and erythropoiesis when humans move from sea level to altitude. The effects of hypoxia on iron balance have been attributed to hepcidin, a central regulator of iron homeostasis. This paper will focus on the molecular mechanisms by which hypoxia affects hepcidin expression, to include a review of the hypoxia inducible factor (HIF/hypoxia response element (HRE system, as well as recent evidence indicating that localized adipose hypoxia due to obesity may affect hepcidin signaling and organismal iron metabolism.

  2. Evaluation of 3D-human skin equivalents for assessment of human dermal absorption of some brominated flame retardants.

    Science.gov (United States)

    Abdallah, Mohamed Abou-Elwafa; Pawar, Gopal; Harrad, Stuart

    2015-11-01

    Ethical and technical difficulties inherent to studies in human tissues are impeding assessment of the dermal bioavailability of brominated flame retardants (BFRs). This is further complicated by increasing restrictions on the use of animals in toxicity testing, and the uncertainties associated with extrapolating data from animal studies to humans due to inter-species variations. To overcome these difficulties, we evaluate 3D-human skin equivalents (3D-HSE) as a novel in vitro alternative to human and animal testing for assessment of dermal absorption of BFRs. The percutaneous penetration of hexabromocyclododecanes (HBCD) and tetrabromobisphenol-A (TBBP-A) through two commercially available 3D-HSE models was studied and compared to data obtained for human ex vivo skin according to a standard protocol. No statistically significant differences were observed between the results obtained using 3D-HSE and human ex vivo skin at two exposure levels. The absorbed dose was low (less than 7%) and was significantly correlated with log Kow of the tested BFR. Permeability coefficient values showed increasing dermal resistance to the penetration of γ-HBCD>β-HBCD>α-HBCD>TBBPA. The estimated long lag times (>30 min) suggests that frequent hand washing may reduce human exposure to HBCDs and TBBPA via dermal contact. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Surface plasmon resonance enhanced light absorption and wavelength tuneable in gold-coated iron oxide spherical nanoparticle

    Science.gov (United States)

    Dasri, Thananchai; Chingsungnoen, Artit

    2018-06-01

    Surface plasmon in nano-sized particles, such as gold, silver, copper and their composites, has recently attracted a great deal of attention due to its possible uses in many applications, especially in life sciences. It is desirable for application devices with a tenability of surface plasmon wavelength and optical properties enhancement. This article presents enhanced optical light absorption and tunable wavelength in gold-coated magnetite (Fe3O4@Au core-shell) nanoparticles embedded in water using the theoretical method of discrete dipole approximation (DDA). The absorption spectra in the wavelengths from 350 to 900 nm were found to be the spectra obtained from Fe3O4@Au core-shell nanoparticles, and when compared with pure Fe3O4 nanoparticles, the surface plasmon resonance can be enhanced and tuned over the entire visible spectrum (viz. 350-800 nm) of the electromagnetic spectrum by varying the Au shell thickness (2-5 nm). Similarly, the Faraday rotation spectra can also be obtained.

  4. Determination of iron in seawater by electrothermal atomic absorption spectrometry and atomic fluorescence spectrometry: A comparative study

    International Nuclear Information System (INIS)

    Cabon, J.Y.; Giamarchi, P.; Le Bihan, A.

    2010-01-01

    Two methods available for direct determination of total Fe in seawater at low concentration level have been examined: electrothermal atomization atomic absorption spectrometry (ETAAS) and electrothermal atomization laser excited atomic fluorescence spectrometry (ETA-LEAFS). In a first part, we have optimized experimental conditions of ETAAS (electrothermal program, matrix chemical modification) for the determination of Fe in seawater by minimizing the chemical interference effects and the magnitude of the simultaneous background absorption signal. By using the best experimental conditions, a detection limit of 80 ng L -1 (20 μL, 3σ) for total Fe concentration was obtained by ETAAS. Using similar experimental conditions (electrothermal program, chemical modification), we have optimized experimental conditions for the determination of Fe by LEAFS. The selected experimental conditions for ETA-LEAFS: excitation wavelength (296.69 nm), noise attenuation and adequate background correction led to a detection limit (3σ) of 3 ng L -1 (i.e. 54 pM) for total Fe concentration with the use a 20 μL seawater sample. For the two methods, concentration values obtained for the analysis of Fe in a NASS-5 (0.2 μg L -1 ) seawater sample were in good agreement with the certified values.

  5. Determination of iron in seawater by electrothermal atomic absorption spectrometry and atomic fluorescence spectrometry: a comparative study.

    Science.gov (United States)

    Cabon, J Y; Giamarchi, P; Le Bihan, A

    2010-04-07

    Two methods available for direct determination of total Fe in seawater at low concentration level have been examined: electrothermal atomization atomic absorption spectrometry (ETAAS) and electrothermal atomization laser excited atomic fluorescence spectrometry (ETA-LEAFS). In a first part, we have optimized experimental conditions of ETAAS (electrothermal program, matrix chemical modification) for the determination of Fe in seawater by minimizing the chemical interference effects and the magnitude of the simultaneous background absorption signal. By using the best experimental conditions, a detection limit of 80 ng L(-1) (20 microL, 3sigma) for total Fe concentration was obtained by ETAAS. Using similar experimental conditions (electrothermal program, chemical modification), we have optimized experimental conditions for the determination of Fe by LEAFS. The selected experimental conditions for ETA-LEAFS: excitation wavelength (296.69 nm), noise attenuation and adequate background correction led to a detection limit (3sigma) of 3 ng L(-1) (i.e. 54 pM) for total Fe concentration with the use a 20 microL seawater sample. For the two methods, concentration values obtained for the analysis of Fe in a NASS-5 (0.2 microg L(-1)) seawater sample were in good agreement with the certified values. Copyright 2010 Elsevier B.V. All rights reserved.

  6. A comparison of simultaneous plasma, atomic absorption, and iron colorimetric determinations of major and trace constituents in acid mine waters

    Science.gov (United States)

    Ball, J.W.; Nordstrom, D. Kirk

    1994-01-01

    Sixty-three water samples collected during June to October 1982 from the Leviathan/Bryant Creek drainage basin were originally analyzed by simultaneous multielement direct-current plasma (DCP) atomic-emission spectrometry, flame atomic-absorption spectrometry, graphite-furnace atomic-absorption spectrometry (GFAAS) (thallium only), ultraviolet-visible spectrometry, and hydride-generation atomic-absorption spectrometry.Determinations were made for the following metallic and semi-metallic constituents: AI, As, B, Ba, Be, Bi, Cd, Ca, Cr, Co, Cu, Fe(11), Fe(total), Li, Pb, Mg, Mn, Mo, Ni, K, Sb, Se, Si, Na, Sr, TI, V, and Zn. These samples were re-analyzed later by simultaneous multielement inductively coupled plasma (ICP) atomic-emission spectrometry and Zeeman-corrected GFAAS to determine the concentrations of many of the same constituents with improved accuracy, precision, and sensitivity. The result of this analysis has been the generation of comparative concentration values for a significant subset of the solute constituents. Many of the more recently determined values replace less-than-detection values for the trace metals; others constitute duplicate analyses for the major constituents. The multiple determinations have yielded a more complete, accurate, and precise set of analytical data. They also have resulted in an opportunity to compare the performance of the plasma-emission instruments operated in their respective simultaneous multielement modes. Flame atomic-absorption spectrometry was judged best for Na and K and hydride-generation atomic-absorption spectrometry was judged best for As because of their lower detection limit and relative freedom from interelement spectral effects. Colorimetric determination using ferrozine as the color agent was judged most accurate, precise, and sensitive for Fe. Cadmium, lead, and vanadium concentrations were too low in this set of samples to enable a determination of whether ICP or DCP is a more suitable technique. Of

  7. In vitro dermal absorption of pyrethroid pesticides in human and rat skin

    International Nuclear Information System (INIS)

    Hughes, Michael F.; Edwards, Brenda C.

    2010-01-01

    Dermal exposure to pyrethroid pesticides can occur during manufacture and application. This study examined the in vitro dermal absorption of pyrethroids using rat and human skin. Dermatomed skin from adult male Long Evans rats or human cadavers was mounted in flow-through diffusion cells, and radiolabeled bifenthrin, deltamethrin or cis-permethrin was applied in acetone to the skin. Fractions of receptor fluid were collected every 4 h. At 24 h, the skins were washed with soap and water to remove unabsorbed chemical. The skin was then solubilized. Two additional experiments were performed after washing the skin; the first was tape-stripping the skin and the second was the collection of receptor fluid for an additional 24 h. Receptor fluid, skin washes, tape strips and skin were analyzed for radioactivity. For rat skin, the wash removed 53-71% of the dose and 26-43% remained in the skin. The cumulative percentage of the dose at 24 h in the receptor fluid ranged from 1 to 5%. For human skin, the wash removed 71-83% of the dose and 14-25% remained in the skin. The cumulative percentage of the dose at 24 h in the receptor fluid was 1-2%. Tape-stripping removed 50-56% and 79-95% of the dose in rat and human skin, respectively, after the wash. From 24-48 h, 1-3% and about 1% of the dose diffused into the receptor fluid of rat and human skin, respectively. The pyrethroids bifenthrin, deltamethrin and cis-permethrin penetrated rat and human skin following dermal application in vitro. However, a skin wash removed 50% or more of the dose from rat and human skin. Rat skin was more permeable to the pyrethroids than human skin. Of the dose in skin, 50% or more was removed by tape-stripping, suggesting that permeation of pyrethroids into viable tissue could be impeded. The percentage of the dose absorbed into the receptor fluid was considerably less than the dose in rat and human skin. Therefore, consideration of the skin type used and fractions analyzed are important when using

  8. Determination of cadmium in human urine by graphite furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Shimizu, Tokuo; Shijo, Yoshio; Sakai, Kaoru

    1981-01-01

    A trace amount of cadmium in human urine was determined by graphite furnace atomic absorption spectrometry. A urine sample (25 ml) was digested with 5 ml of HNO 3 and 30 ml of H 2 O 2 in a long-neck flask on a hot-plate (200 0 C), then diluted to 50 ml. The standard addition method was carried out before digesting. Ten μl of the resulted solution was injected into a tube treated with tungsten carbide, and the cadmium signal was measured with the ramp mode atomization. Interference induced by organic materials in urine was avoided by HNO 3 -H 2 O 2 digestion. Interference induced by inorganic salts could be reduced by 2-fold dilution and tungsten carbide treatment. The cadmium signal was separated sufficiently from the molecular absorption due to NaCl etc. by the ramp mode atomization. Since the blank level of H 2 O 2 was relatively high, the determination was limited to about 0.1 μg/l. The coefficient of variation was 1.76% at 0.36 μg/l in 24 h human urine (n = 4). The time required was (8 -- 10)h. The precision of this method was higher than those of direct methods, and the reasonable values of urine levels of cadmium were obtained. (author)

  9. Human in vivo and in vitro studies on gastrointestinal absorption of titanium dioxide nanoparticles.

    Science.gov (United States)

    Jones, Kate; Morton, Jackie; Smith, Ian; Jurkschat, Kerstin; Harding, Anne-Helen; Evans, Gareth

    2015-03-04

    The study was designed to conduct human in vivo and in vitro studies on the gastrointestinal absorption of nanoparticles, using titanium dioxide as a model compound, and to compare nanoparticle behaviour with that of larger particles. A supplier's characterisation data may not fully describe a particle formulation. Most particles tested agreed with their supplied characterisation when assessed by particle number but significant proportions of 'nanoparticle formulations' were particles >100nm when assessed by particle weight. Oral doses are measured by weight and it is therefore important that the weight characterisation is taken into consideration. The human volunteer studies demonstrated that very little titanium dioxide is absorbed gastrointestinally after an oral challenge. There was no demonstrable difference in absorption for any of the three particle sizes tested. All tested formulations were shown to agglomerate in simulated gastric fluid, particularly in the smaller particle formulations. Further agglomeration was observed when dispersing formulations in polymeric or elemental foods. Virtually no translocation of titanium dioxide particles across the cell layer was demonstrated. This study found no evidence that nanoparticulate titanium dioxide is more likely to be absorbed in the gut than micron-sized particles. Crown Copyright © 2015. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Gastrointestinal absorption of plutonium and uranium in fed and fasted adult baboons and mice: application to humans

    International Nuclear Information System (INIS)

    Bhattacharyya, M.H.; Larsen, R.P.; Oldham, R.D.; Cohen, N.; Ralston, L.G.; Moretti, E.S.; Ayres, L.

    1989-01-01

    Gastrointestinal (GI) absorption values of plutonium and uranium were determined in fed and fasted adult baboons and mice. For both baboons and mice, the GI absorptions of plutonium and uranium were 10 to 20 times higher in 24 h fasted animals than in fed ones. For plutonium, GI absorption values in baboons were almost identical to those in mice for both fed and fasted conditions, and values for fed animals agreed with estimates for humans. For uranium, GI absorption values in fed and fasted baboons were 6 to 7 times higher than those in mice, and agreed well with those fed and fasted humans. For one baboon that was not given its morning meal, plutonium absorption 2 h after the start of the active phase was the same as that in the 24 h fasted animals. In contrast, for baboons that received a morning meal, plutonium absorption did not rise to the value of 24 h fasted baboons even 8 h after the meal. We conclude that GI absorption values for plutonium and uranium in adult baboons are good estimates of the values in humans and that the values for the fasted condition should be used to set standards for oral exposure of persons in the workplace. (author)

  11. Iron oxide nanoparticles induce human microvascular endothelial cell permeability through reactive oxygen species production and microtubule remodeling

    Directory of Open Access Journals (Sweden)

    Shi Xianglin

    2009-01-01

    Full Text Available Abstract Background Engineered iron nanoparticles are being explored for the development of biomedical applications and many other industry purposes. However, to date little is known concerning the precise mechanisms of translocation of iron nanoparticles into targeted tissues and organs from blood circulation, as well as the underlying implications of potential harmful health effects in human. Results The confocal microscopy imaging analysis demonstrates that exposure to engineered iron nanoparticles induces an increase in cell permeability in human microvascular endothelial cells. Our studies further reveal iron nanoparticles enhance the permeability through the production of reactive oxygen species (ROS and the stabilization of microtubules. We also showed Akt/GSK-3β signaling pathways are involved in iron nanoparticle-induced cell permeability. The inhibition of ROS demonstrate ROS play a major role in regulating Akt/GSK-3β – mediated cell permeability upon iron nanoparticle exposure. These results provide new insights into the bioreactivity of engineered iron nanoparticles which can inform potential applications in medical imaging or drug delivery. Conclusion Our results indicate that exposure to iron nanoparticles induces an increase in endothelial cell permeability through ROS oxidative stress-modulated microtubule remodeling. The findings from this study provide new understandings on the effects of nanoparticles on vascular transport of macromolecules and drugs.

  12. AN INVESTIGATION OF THE PROTONATION STATES OF HUMAN LACTOFERRIN IRON-BINDING PROTEIN

    Directory of Open Access Journals (Sweden)

    Lilia Anghel

    2015-06-01

    Full Text Available In this study, the protonation states of ionizable groups of human lactoferrin in various conformations were investigated theoretically, at physiological pH (7.365. These calculations show that the transition of the protein from a conformation to another one is accompanied by changes in the protonation state of specific amino acid residues. Analysis of the pKa calculatons underlined the importance of participation of two arginines and one lysine in the opening / closing of the protein. In addition, it was found that the mechanism of iron release depends on the protonation state of TYR-192. Protonated state of this residue in the closed form of lactoferrin will trigger the opening of protein and release of iron ions.

  13. New experimental data on the human dermal absorption of Simazine and Carbendazim help to refine the assessment of human exposure.

    Science.gov (United States)

    Bányiová, Katarína; Nečasová, Anežka; Kohoutek, Jiří; Justan, Ivan; Čupr, Pavel

    2016-02-01

    Due to their widespread usage, people are exposed to pesticides on a daily basis. Although these compounds may have adverse effects on their health, there is a gap in the data and the methodology needed to reliably quantify the risks of non-occupational human dermal exposure to pesticides. We used Franz cells and human skin in order to measure the dermal absorption kinetics (steady-state flux, lag time and permeability coefficient) of Carbendazim and Simazine. These parameters were then used to refine the dermal exposure model and a probabilistic simulation was used to quantify risks resulting from exposure to pesticide-polluted waters. The experimentally derived permeability coefficient was 0.0034 cm h(-1) for Carbendazim and 0.0047 cm h(-1) for Simazine. Two scenarios (varying exposure duration and concentration, i.e. environmentally relevant and maximum solubility) were used to quantify the human health risks (hazard quotients) for Carbendazim and Simazine. While no risks were determined in the case of either scenario, the permeability coefficient, which is concentration independent and donor, formulation, compound and membrane specific, may be used in other scenarios and exposure models to quantify more precisely the dermally absorbed dose during exposure to polluted water. To the best of our knowledge, the dermal absorption kinetics parameters defined here are being published for the first time. The usage of experimental permeability parameters in combination with probabilistic risk assessment thus provides a new tool for quantifying the risks of human dermal exposure to pesticides. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Simulations of iron K pre-edge X-ray absorption spectra using the restricted active space method.

    Science.gov (United States)

    Guo, Meiyuan; Sørensen, Lasse Kragh; Delcey, Mickaël G; Pinjari, Rahul V; Lundberg, Marcus

    2016-01-28

    The intensities and relative energies of metal K pre-edge features are sensitive to both geometric and electronic structures. With the possibility to collect high-resolution spectral data it is important to find theoretical methods that include all important spectral effects: ligand-field splitting, multiplet structures, 3d-4p orbital hybridization, and charge-transfer excitations. Here the restricted active space (RAS) method is used for the first time to calculate metal K pre-edge spectra of open-shell systems, and its performance is tested against on six iron complexes: [FeCl6](n-), [FeCl4](n-), and [Fe(CN)6](n-) in ferrous and ferric oxidation states. The method gives good descriptions of the spectral shapes for all six systems. The mean absolute deviation for the relative energies of different peaks is only 0.1 eV. For the two systems that lack centrosymmetry [FeCl4](2-/1-), the ratios between dipole and quadrupole intensity contributions are reproduced with an error of 10%, which leads to good descriptions of the integrated pre-edge intensities. To gain further chemical insight, the origins of the pre-edge features have been analyzed with a chemically intuitive molecular orbital picture that serves as a bridge between the spectra and the electronic structures. The pre-edges contain information about both ligand-field strengths and orbital covalencies, which can be understood by analyzing the RAS wavefunction. The RAS method can thus be used to predict and rationalize the effects of changes in both the oxidation state and ligand environment in a number of hard X-ray studies of small and medium-sized molecular systems.

  15. Direct analysis of Antarctic krill by slurry sampling: determination of copper, iron, manganese and zinc by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Alves Flávia L.

    2000-01-01

    Full Text Available Slurry sampling in combination with flame atomic absorption spectrometry was employed for the direct determination of four essential trace elements, namely Cu, Fe, Mn and Zn in Antarctic krill. The effect of instrumental operating conditions and slurry sampling preparation on the analytical signal was investigated. For the determination of Cu, Fe and Zn, samples were suspended in a solution containing 2 mol L-1 HNO3. In the case of Mn, 4 mol L-1 HNO3 was necessary for the preparation of the slurry. The precision between sample replicates was better than 5%. The method was applied to the direct determination of Cu, Fe, Mn and Zn in Antarctic krill samples using aqueous reference solutions to prepare the calibration curves. The results obtained were in good agreement with those achieved by FAAS and ICP-AES after microwave-assisted wet digestion of the krill samples. The detection limits were 4.5, 1.0, 4.9 and 8.4 mug L-1 for Cu, Zn, Mn and Fe, respectively.

  16. Vibrational, X-ray absorption, and Mössbauer spectra of sulfate minerals from the weathered massive sulfide deposit at Iron Mountain, California

    Science.gov (United States)

    Majzlan, Juraj; Alpers, Charles N.; Bender Koch, Christian; McCleskey, R. Blaine; Myneni, Satish B.C.; Neil, John M.

    2014-01-01

    The Iron Mountain Mine Superfund site in California is a prime example of an acid mine drainage (AMD) system with well developed assemblages of sulfate minerals typical for such settings. Here we present and discuss the vibrational (infrared), X-ray absorption, and Mössbauer spectra of a number of these phases, augmented by spectra of a few synthetic sulfates related to the AMD phases. The minerals and related phases studied in this work are (in order of increasing Fe2O3/FeO): szomolnokite, rozenite, siderotil, halotrichite, römerite, voltaite, copiapite, monoclinic Fe2(SO4)3, Fe2(SO4)3·5H2O, kornelite, coquimbite, Fe(SO4)(OH), jarosite and rhomboclase. Fourier transform infrared spectra in the region 750–4000 cm−1 are presented for all studied phases. Position of the FTIR bands is discussed in terms of the vibrations of sulfate ions, hydroxyl groups, and water molecules. Sulfur K-edge X-ray absorption near-edge structure (XANES) spectra were collected for selected samples. The feature of greatest interest is a series of weak pre-edge peaks whose position is determined by the number of bridging oxygen atoms between Fe3+ octahedra and sulfate tetrahedra. Mössbauer spectra of selected samples were obtained at room temperature and 80 K for ferric minerals jarosite and rhomboclase and mixed ferric–ferrous minerals römerite, voltaite, and copiapite. Values of Fe2+/[Fe2+ + Fe3+] determined by Mössbauer spectroscopy agree well with those determined by wet chemical analysis. The data presented here can be used as standards in spectroscopic work where spectra of well-characterized compounds are required to identify complex mixtures of minerals and related phases.

  17. Opacity of iron, nickel, and copper plasmas in the x-ray wavelength range: Theoretical interpretation of 2p-3d absorption spectra

    International Nuclear Information System (INIS)

    Blenski, T.; Loisel, G.; Poirier, M.; Thais, F.; Arnault, P.; Caillaud, T.; Fariaut, J.; Gilleron, F.; Pain, J.-C.; Porcherot, Q.; Reverdin, C.; Silvert, V.; Villette, B.; Bastiani-Ceccotti, S.; Turck-Chieze, S.; Foelsner, W.; Gaufridy de Dortan, F. de

    2011-01-01

    This paper deals with theoretical studies on the 2p-3d absorption in iron, nickel, and copper plasmas related to LULI2000 (Laboratoire pour l'Utilisation des Lasers Intenses, 2000J facility) measurements in which target temperatures were of the order of 20 eV and plasma densities were in the range 0.004-0.01 g/cm 3 . The radiatively heated targets were close to local thermodynamic equilibrium (LTE). The structure of 2p-3d transitions has been studied with the help of the statistical superconfiguration opacity code sco and with the fine-structure atomic physics codes hullac and fac. A new mixed version of the sco code allowing one to treat part of the configurations by detailed calculation based on the Cowan's code rcg has been also used in these comparisons. Special attention was paid to comparisons between theory and experiment concerning the term features which cannot be reproduced by sco. The differences in the spin-orbit splitting and the statistical (thermal) broadening of the 2p-3d transitions have been investigated as a function of the atomic number Z. It appears that at the conditions of the experiment the role of the term and configuration broadening was different in the three analyzed elements, this broadening being sensitive to the atomic number. Some effects of the temperature gradients and possible non-LTE effects have been studied with the help of the radiative-collisional code scric. The sensitivity of the 2p-3d structures with respect to temperature and density in medium-Z plasmas may be helpful for diagnostics of LTE plasmas especially in future experiments on the Δn=0 absorption in medium-Z plasmas for astrophysical applications.

  18. Influence of evaporation and solvent mixtures on the absorption of toluene and n-butanol in human skin in vitro.

    Science.gov (United States)

    Boman, A; Maibach, H I

    2000-03-01

    The influence of forced ventilation on the percutaneous absorption of butanol and toluene was studied in vitro. Human skin was exposed to the neat solvents and the solvents in binary mixtures with each other and in ternary mixtures with chloroform:methanol. The exposure was either unventilated or ventilated with various flow rates. At the ventilated exposure the skin absorption of all solvents and solvent mixtures was markedly reduced compared to unventilated exposure. Exposure with solvent mixtures increased the amounts of solvent absorbed as well as absorption rates. The absorption of the butanol component was most influenced. Increase in absorption was 11 to 9 times depending on whether toluene or chloroform/methanol was cosolvent. There was also an interindividual variation of absorption rate, varying with a factor of 3.5 for toluene and 4.3 for n-butanol within the 3 skin donors used. Skin absorption of volatile organic solvents at continuous ventilated conditions is related to their volatility and to the ventilation rate.A sufficient workplace ventilation is an important occupational hygienic measure not only to reduce exposure via respiration but to reduce absorption via the skin of volatile compounds as well.

  19. Investigation of human teeth with respect to the photon interaction, energy absorption and buildup factor

    Energy Technology Data Exchange (ETDEWEB)

    Kurudirek, Murat, E-mail: mkurudirek@gmail.co [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey); Topcuoglu, Sinan [Faculty of Dentistry, Department of Endodontic, Ataturk University, 25240 Erzurum (Turkey)

    2011-05-15

    The effective atomic numbers and electron densities of human teeth have been calculated for total photon interaction (Z{sub PI{sub e{sub f{sub f}}}},Ne{sub PI{sub e{sub f{sub f}}}}) and photon energy absorption (Z{sub PEA{sub e{sub f{sub f}}}},Z{sub RW{sub e{sub f{sub f}}}}Ne{sub PEA{sub e{sub f{sub f}}}}) in the energy region 1 keV-20 MeV. Besides, the energy absorption (EABF) and exposure (EBF) buildup factors have been calculated for these samples by using the geometric progression fitting approximation in the energy region 0.015-15 MeV up to 40 mfp (mean free path). Wherever possible the results were compared with experiment. Effective atomic numbers (Z{sub PI{sub e{sub f{sub f}}}}) of human teeth were calculated using different methods. Discrepancies were noted in Z{sub PI{sub e{sub f{sub f}}}} between the direct and interpolation methods in the low and high energy regions where absorption processes dominate while good agreement was observed in intermediate energy region where Compton scattering dominates. Significant variations up to 22% were observed between Z{sub PI{sub e{sub f{sub f}}}} and Z{sub PEA{sub e{sub f{sub f}}}} in the energy region 30-150 keV which is the used energy range in dental cone beam computed tomography (CBCT) X-ray machines. The Z{sub eff} values of human teeth were found to relatively vary within 1% if different laser treatments are applied. In this variation, the Er:YAG laser treated samples were found to be less effected than Nd:YAG laser treated ones when compared with control group. Relative differences between EABF and EBF were found to be significantly high in the energy region 60 keV-1 MeV even though they have similar variations with respect to the different parameters viz. photon energy, penetration depth.

  20. Skin-mimetic chromatography for prediction of human percutaneous absorption of biologically active compounds occurring in medicinal plant extracts.

    Science.gov (United States)

    Stepnik, Katarzyna; Malinowska, Irena

    2017-04-01

    The main aim of this study was to predict quantitatively human percutaneous absorption of chosen compounds commonly occurring in plants which can be used as medicinal extracts in the drug and beauty industries. The most important human percutaneous descriptors, i.e. logK p (logarithm of the water/skin partition coefficient) and logJ max (logarithm of the maximum flux of solutes penetrating the skin), of fatty acids and polyphenols were determined using both in vitro and in silico methods. For in vitro determination of human percutaneous absorption, micellar liquid chromatography based on hexadecyltrimethylammonium bromide, sodium dodecyl sulfate and polyoxyethylene (23) lauryl ether (Brij35) was used. Human percutaneous absorption was characterized by entirely new QSAR/QRAR models based on retention, lipophilic, steric and electronic data as well as on the linear free energy relationship parameters. Many different correlations between human skin absorption and different physicochemical parameters were performed, e.g. the in silico estimated logK p value was correlated with the retention parameter logk w (logarithm of the retention factor extrapolated to pure water) from the systems imitating a cutaneous environment (R 2  = 0.92). Moreover, the influence of lipophilicity on percutaneous absorption was examined. The obtained correlation was excellent (R 2  = 0.95). Copyright © 2016 John Wiley & Sons, Ltd.

  1. SPECTROPHOTOMETRY OF HEMOGLOBIN - ABSORPTION-SPECTRA OF RAT OXYHEMOGLOBIN, DEOXYHEMOGLOBIN, CARBOXYHEMOGLOBIN, AND METHEMOGLOBIN

    NARCIS (Netherlands)

    ZIJLSTRA, WG; BUURSMA, A; FALKE, HE; CATSBURG, JF

    The absorptivity at 540 nm of methemoglobincyanide from rat blood was determined on the basis of iron and found to be equal to the established value for human methemoglobincyanide (11,01/mmol/cm). On this basis the absorption spectra of the common derivatives were determined for rat hemoglobin.

  2. Spectrophotometry of hemoglobin : Absorption spectra of bovine oxyhemoglobin, deoxyhemoglobin, carboxyhemoglobin, and methemoglobin

    NARCIS (Netherlands)

    Zijlstra, WG; Buursma, A

    1997-01-01

    The absorptivity at 540 nm of bovine hemiglobincyanide (cyanmethemoglobin) was determined on the basis of the iron content and found to be equal to the established value for human hemiglobincyanide (11.0 L . mmol(-1).cm(-1)). On this basis the absorption spectra of the common derivatives were

  3. A lactic acid-fermented oat gruel increases non-haem iron absorption from a phytate-rich meal in healthy women of childbearing age

    DEFF Research Database (Denmark)

    Bering, S.; Suchdev, S.; Sjoltov, L.

    2006-01-01

    Lactic acid-fermented foods have been shown to increase Fe absorption in human subjects, possibly by lowering pH, activation of phytases, and formation of soluble complexes of Fe and organic acids. We tested the effect of an oat gruel fermented with Lactobacillus plantarum 299v on non-haem Fe...... absorption from a low-Fe bioavailability meal compared with a pasteurised, fermented oat gruel and non-fermented oat gruels. In a cross-over trial twenty-four healthy women with a mean age of 25 (sd 4) years were served (A) fermented gruel, (B) pasteurised fermented gruel, (C) pH-adjusted non-fermented gruel......, and (D) non-fermented gruel with added organic acids. The meals were extrinsically labelled with Fe-55 or Fe-59 and consumed on 4 consecutive days, for example, in the order ABBA or BAAB followed by CDDC or DCCD in a second period. Fe absorption was determined from isotope activities in blood samples...

  4. Estimation of lead and zinc in human hair using atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Kazi, S.; Kazi, T.G.; Kazi, G.H.

    1993-01-01

    Trace elements analysis in hair can be useful in studying the impact of environmental and dietary factors on human in general for lead and zinc content in hair. Samples of people of different age groups, sex with varied living habits of the individual living in different areas of Sind, urban as well as rural areas were of special interest to be studied to find correlation of socioeconomic factors and the presence of these elements in hair samples. The purpose of this study was to determine whether age, sex and physiological status and environmental pollution affect composition of hair. The method of sample preparation and use of atomic absorption techniques providing unequivocal and direct estimation of metals in ppm/ppb range to arrive upon conclusion. (author)

  5. Gamma-ray energy absorption and exposure buildup factor studies in some human tissues with endometriosis

    Energy Technology Data Exchange (ETDEWEB)

    Kurudirek, Murat, E-mail: mkurudirek@gmail.co [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey); Dogan, Bekir [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey); Ingec, Metin [Faculty of Medicine, Department of Obstetrics and Gynecology, Ataturk University, 25240 Erzurum (Turkey); Ekinci, Neslihan; Ozdemir, Yueksel [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey)

    2011-02-15

    Human tissues with endometriosis have been analyzed in terms of energy absorption (EABF) and exposure (EBF) buildup factors using the five-parameter geometric progression (G-P) fitting formula in the energy region 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path). Chemical compositions of the tissue samples were determined using a wavelength dispersive X-ray fluorescence spectrometer (WDXRFS). Possible conclusions were drawn due to significant variations in EABF and EBF for the selected tissues when photon energy, penetration depth and chemical composition changed. Buildup factors so obtained may be of use when the method of choice for treatment of endometriosis is radiotherapy.

  6. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... normally stores but has used up. Increase your intake of vitamin C to help your body absorb iron. Avoid drinking black tea, which reduces iron absorption. Other treatments If you have chronic kidney disease and iron-deficiency anemia, your doctor may recommend ...

  7. Expression of iron-related genes in human brain and brain tumors

    Directory of Open Access Journals (Sweden)

    Britton Robert S

    2009-04-01

    Full Text Available Abstract Background Defective iron homeostasis may be involved in the development of some diseases within the central nervous system. Although the expression of genes involved in normal iron balance has been intensively studied in other tissues, little is known about their expression in the brain. We investigated the mRNA levels of hepcidin (HAMP, HFE, neogenin (NEO1, transferrin receptor 1 (TFRC, transferrin receptor 2 (TFR2, and hemojuvelin (HFE2 in normal human brain, brain tumors, and astrocytoma cell lines. The specimens included 5 normal brain tissue samples, 4 meningiomas, one medulloblastoma, 3 oligodendrocytic gliomas, 2 oligoastrocytic gliomas, 8 astrocytic gliomas, and 3 astrocytoma cell lines. Results Except for hemojuvelin, all genes studied had detectable levels of mRNA. In most tumor types, the pattern of gene expression was diverse. Notable findings include high expression of transferrin receptor 1 in the hippocampus and medulla oblongata compared to other brain regions, low expression of HFE in normal brain with elevated HFE expression in meningiomas, and absence of hepcidin mRNA in astrocytoma cell lines despite expression in normal brain and tumor specimens. Conclusion These results indicate that several iron-related genes are expressed in normal brain, and that their expression may be dysregulated in brain tumors.

  8. Oleic acid and docosahexaenoic acid cause an increase in the paracellular absorption of hydrophilic compounds in an experimental model of human absorptive enterocytes

    International Nuclear Information System (INIS)

    Aspenstroem-Fagerlund, Bitte; Ring, Linda; Aspenstroem, Pontus; Tallkvist, Jonas; Ilbaeck, Nils-Gunnar; Glynn, Anders W.

    2007-01-01

    Surface active compounds present in food possibly have the ability to enhance the absorption of water soluble toxic agents. Therefore, we investigated whether fatty acids such as oleic acid and docosahexaenoic acid (DHA), both commonly present in food, negatively affect the integrity of tight junctions (TJ) in the intestinal epithelium and thereby increase the absorption of poorly absorbed hydrophilic substances. Caco-2 cells, which are derived from human absorptive enterocytes, were grown on permeable filters for 20-25 days. Differentiated cell monolayers were apically exposed for 90 min to mannitol in emulsions of oleic acid (5, 15 or 30 mM) or DHA (5, 15 or 30 mM) in an experimental medium with or without Ca 2+ and Mg 2+ . Absorption of 14 C-mannitol increased and trans-epithelial electrical resistance (TEER) decreased in cell monolayers exposed to oleic acid and DHA, compared to controls. Cytotoxicity, measured as leakage of LDH, was higher in groups exposed to 30 mM oleic acid and all concentrations of DHA. Morphology of the cell monolayers was studied by using fluorescence microscopy. Exposure of cell monolayers to 5 mM DHA for 90 min resulted in a profound alteration of the cell-cell contacts as detected by staining the cells for β-catenin. Oleic acid (30 mM) treatment also induced dissolution of the cell-cell contacts but the effect was not as pronounced as with DHA. Cell monolayers were also exposed for 180 min to 250 nM cadmium (Cd) in emulsions of oleic acid (5 or 30 mM) or DHA (1 or 5 mM), in an experimental medium with Ca 2+ and Mg 2+ . Retention of Cd in Caco-2 cells was higher after exposure to 5 mM oleic acid but lower after exposure to 30 mM oleic acid and DHA. Absorption of Cd through the monolayers increased after DHA exposure but not after exposure to oleic acid. Our results indicate that fatty acids may compromise the integrity of the intestinal epithelium and that certain lipids in food may enhance the paracellular absorption of poorly

  9. Temperature modulation of the visible and near infrared absorption and scattering coefficients of human skin.

    Science.gov (United States)

    Khalil, Omar S; Yeh, Shu-Jen; Lowery, Michael G; Wu, Xiaomao; Hanna, Charles F; Kantor, Stanislaw; Jeng, Tzyy-Wen; Kanger, Johannes S; Bolt, Rene A; de Mul, Frits F

    2003-04-01

    We determine temperature effect on the absorption and reduced scattering coefficients (mu(a) and mu(s)(')) of human forearm skin. Optical and thermal simulation data suggest that mu( a) and mu(s)(') are determined within a temperature-controlled depth of approximately 2 mm. Cutaneous mu(s)(') change linearly with temperature. Change in mu(a) was complex and irreversible above body normal temperatures. Light penetration depth (delta) in skin increased on cooling, with considerable person-to-person variations. We attribute the effect of temperature on mu(s)(') to change in refractive index mismatch, and its effect on mu(a) to perfusion changes. The reversible temperature effect on mu (s)(' ) was maintained during more than 90 min. contact between skin and the measuring probe, where temperature was modulated between 38 and 22 degrees C for multiple cycles While temperature modulated mu(s)(' ) instantaneously and reversibly, mu(a) exhibited slower response time and consistent drift. There was a statistically significant upward drift in mu(a) and a mostly downward drift in mu( s)(') over the contact period. The drift in temperature-induced fractional change in mu(s)(') was less statistically significant than the drift in mu(s)('). Deltamu( s)(') values determined under temperature modulation conditions may have less nonspecific drift than mu(s)(') which may have significance for noninvasive determination of analytes in human tissue.

  10. Determination of molybdenum in human urine by electrothermal atomization atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Pita Calvo, C.; Bermejo Barrera, P.; Bermejo Barrera, A.

    1995-01-01

    Various matrix modifiers were investigated for the determination of molybdenum in human urine samples by electrothermal atomization atomic absorption spectrometry. Methods with nitric acid, barium difluoride, magnesium nitrate, palladium-magnesium nitrate and palladium-hydroxylamine hydrochloride were studied by introducing the urine samples directly into the graphite furnace with 0.3% Triton X-100. The charring and atomization curves, the amount of modifier and the calibration and addition graphs were studied in all instances. The precision, accuracy and chemical interferences of the methods were also investigated. The matrix interferences have been removed with the modifiers barium difluoride, palladium-magnesium nitrate and palladium-hydroxylamine hydrochloride. The limits of detection and quantification were 0.2 and 0.7 μg l -1 , respectively, for these modifiers. The characteristic masses were 14.1, 18.0 and 14.9 pg of Mo for palladium-magnesium nitrate, palladium-hydroxylamine hydrochloride and barium difluoride, respectively. The method with palladium-magnesium nitrate has been applied to the study of the amount of molybdenum in human urine samples. The molybdenum levels found lie between 4.8-205.6 μg l -1

  11. Human intestinal absorption of imidacloprid with Caco-2 cells as enterocyte model

    International Nuclear Information System (INIS)

    Brunet, Jean-Luc; Maresca, Marc; Fantini, Jacques; Belzunces, Luc P.

    2004-01-01

    In order to assess the risk to mammals of a chronic exposure to imidacloprid (IMI), we investigated its absorption with the human intestinal Caco-2 cell line. Measurements of transepithelial transport revealed an apparent permeability coefficient of 21.6 x 10 -6 ± 3.2 x 10 -6 cm/s reflecting a 100% absorption. The comparison of apical to basal (A-B) and basal to apical (B-A) transports showed that the monolayer presents a basal to apical polarized transport. Studies of apical uptake demonstrated that the transport was concentration-dependent and not saturable from 5 to 200 μM. Arrhenius plot analysis revealed two apparent activation energies, E a(4-12deg . C) = 63.8 kJ/mol and E a(12-37deg. C) 18.2 kJ/mol, suggesting two temperature-dependent processes. IMI uptake was equivalent when it was performed at pH 6.0 or 7.4. Depletion of Na + from the transport buffer did not affect the uptake, indicating that a sodium-dependent transporter was not involved. Decrease of uptake with sodium-azide or after cell surface trypsin (Ti) treatment suggested the involvement of a trypsin-sensitive ATP-dependent transporter. Investigations on apical efflux demonstrated that initial velocities paralleled the increase of loading concentrations. A cell surface trypsin treatment did not affect the apical efflux. The lack of effect when the efflux was performed against an IMI concentration gradient suggested that an energy-dependent transporter was involved. However, the inhibition of P-glycoproteins (P-gp) and multidrug resistance-associated proteins (MRP) by taxol, vincristine, and daunorubicine had no effect on IMI intracellular accumulation suggesting the involvement of transporters distinct from classical ATP binding cassette transport (ABC-transport) systems. All results suggest that IMI is strongly absorbed in vivo by inward and outward active transporters

  12. Interactions of human hemoglobin with charged ligand-functionalized iron oxide nanoparticles and effect of counterions

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Goutam, E-mail: ghoshg@yahoo.com [UGC-DAE Consortium for Scientific Research, Mumbai Centre (India); Panicker, Lata [Bhabha Atomic Research Centre, Solid State Physics Division (India)

    2014-12-15

    Human hemoglobin is an important metalloprotein. It has tetrameric structure with each subunit containing a ‘heme’ group which carries oxygen and carbon dioxide in blood. In this work, we have investigated the interactions of human hemoglobin (Hb) with charged ligand-functionalized iron oxide nanoparticles and the effect of counterions, in aqueous medium. Several techniques like DLS and ζ-potential measurements, UV–vis, fluorescence, and CD spectroscopy have been used to characterize the interaction. The nanoparticle size was measured to be in the range of 20–30 nm. Our results indicated the binding of Hb with both positively as well as negatively charged ligand-functionalized iron oxide nanoparticles in neutral aqueous medium which was driven by the electrostatic and the hydrophobic interactions. The electrostatic binding interaction was not seen in phosphate buffer at pH 7.4. We have also observed that the ‘heme’ groups of Hb remained unaffected on binding with charged nanoparticles, suggesting the utility of the charged ligand-functionalized nanoparticles in biomedical applications.

  13. Localization and role of NPC1L1 in cholesterol absorption in human intestine.

    Science.gov (United States)

    Sané, Alain Théophile; Sinnett, Daniel; Delvin, Edgard; Bendayan, Moise; Marcil, Valérie; Ménard, Daniel; Beaulieu, Jean-François; Levy, Emile

    2006-10-01

    Recent studies have documented the presence of Niemann-Pick C1-Like 1 (NPC1L1) in the small intestine and its capacity to transport cholesterol in mice and rats. The current investigation was undertaken to explore the localization and function of NPC1L1 in human enterocytes. Cell fractionation experiments revealed an NPC1L1 association with apical membrane of the enterocyte in human jejunum. Signal was also detected in lysosomes, endosomes, and mitochondria. Confirmation of cellular NPC1L1 distribution was obtained by immunocytochemistry. Knockdown of NPC1L1 caused a decline in the ability of Caco-2 cells to capture micellar [(14)C]free cholesterol. Furthermore, this NPC1L1 suppression resulted in increased and decreased mRNA levels and activity of HMG-CoA reductase, the rate-limiting step in cholesterol synthesis, and of ACAT, the key enzyme in cholesterol esterification, respectively. An increase was also noted in the transcriptional factor sterol-regulatory element binding protein that modulates cholesterol homeostasis. Efforts were devoted to define the impact of NPC1L1 knockdown on other mediators of cholesterol uptake. RT-PCR evidence is presented to show the significant decrease in the levels of scavenger receptor class B type I (SR-BI) with no changes in ABCA1, ABCG5, and cluster determinant 36 in NPC1L1-deficient Caco-2 cells. Together, our data suggest that NPC1L1 contributes to intestinal cholesterol homeostasis and possibly cooperates with SR-BI to mediate cholesterol absorption in humans.

  14. Iron species determination by task-specific ionic liquid-based in situ solvent formation dispersive liquid-liquid microextraction combined with flame atomic absorption spectrometry.

    Science.gov (United States)

    Sadeghi, Susan; Ashoori, Vahid

    2017-10-01

    The task-specific ionic liquid (TSIL) of 1-ethyl-3-methylimidazolium bromide functionalized with 8-hydroxyquinoline was used as a chelating agent and extracting solvent for dispersive liquid-liquid microextraction and subsequent determination of Fe(III) by flame atomic absorption spectrometry. The in situ solvent formation of TSIL using KPF 6 provided the desired water-immiscible ionic liquid. The total Fe concentration could be determined after pre-oxidation of Fe(II) to Fe(III). Various factors affecting the proposed extraction procedure were optimized. The proposed analytical conditions were: sample pH 5, TSIL amount 0.3% (w/v), KPF 6 amount 0.15% (w/v), anti-sticking 0.1% (w/v) and salt concentration 5% (w/v). Under optimal conditions, the linear dynamic ranges for Fe(III) and total Fe were 20-80 and 20-110 ng mL -1 , respectively, with a detection limit of 6.9 ng mL -1 for Fe(III) and relative standard deviation of 2.2%. The proposed method was successfully applied to the determination of trace Fe(III) in water (underground, tap, refined water and artificial sea water) and beverage (apple, tomato, and tea) samples. The developed method offers advantages such as simplicity, ease of operation, and extraction of Fe(III) from aqueous solutions without the use of organic solvent. It was successfully applied for iron speciation in different real samples. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  15. Energy absorption buildup factors of human organs and tissues at energies and penetration depths relevant for radiotherapy and diagnostics

    DEFF Research Database (Denmark)

    Manohara, S. R.; Hanagodimath, S. M.; Gerward, Leif

    2011-01-01

    Energy absorption geometric progression (GP) fitting parameters and the corresponding buildup factors have been computed for human organs and tissues, such as adipose tissue, blood (whole), cortical bone, brain (grey/white matter), breast tissue, eye lens, lung tissue, skeletal muscle, ovary......, testis, soft tissue, and soft tissue (4-component), for the photon energy range 0.015-15 MeV and for penetration depths up to 40 mfp (mean free path). The chemical composition of human organs and tissues is seen to influence the energy absorption buildup factors. It is also found that the buildup factor...... of human organs and tissues changes significantly with the change of incident photon energy and effective atomic number, Zeff. These changes are due to the dominance of different photon interaction processes in different energy regions and different chemical compositions of human organs and tissues...

  16. Effects of Iron Overload on the Activity of Na,K-ATPase and Lipid Profile of the Human Erythrocyte Membrane.

    Directory of Open Access Journals (Sweden)

    Leilismara Sousa

    Full Text Available Iron is an essential chemical element for human life. However, in some pathological conditions, such as hereditary hemochromatosis type 1 (HH1, iron overload induces the production of reactive oxygen species that may lead to lipid peroxidation and a change in the plasma-membrane lipid profile. In this study, we investigated whether iron overload interferes with the Na,K-ATPase activity of the plasma membrane by studying erythrocytes that were obtained from the whole blood of patients suffering from iron overload. Additionally, we treated erythrocytes of normal subjects with 0.8 mM H2O2 and 1 μM FeCl3 for 24 h. We then analyzed the lipid profile, lipid peroxidation and Na,K-ATPase activity of plasma membranes derived from these cells. Iron overload was more frequent in men (87.5% than in women and was associated with an increase (446% in lipid peroxidation, as indicated by the amount of the thiobarbituric acid reactive substances (TBARS and an increase (327% in the Na,K-ATPase activity in the plasma membrane of erythrocytes. Erythrocytes treated with 1 μM FeCl3 for 24 h showed an increase (132% in the Na,K-ATPase activity but no change in the TBARS levels. Iron treatment also decreased the cholesterol and phospholipid content of the erythrocyte membranes and similar decreases were observed in iron overload patients. In contrast, erythrocytes treated with 0.8 mM H2O2 for 24 h showed no change in the measured parameters. These results indicate that erythrocytes from patients with iron overload exhibit higher Na,K-ATPase activity compared with normal subjects and that this effect is specifically associated with altered iron levels.

  17. Analysis of iron storage proteins in chicken liver and spleen tissues in comparison with human liver ferritin by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Oshtrakh, M.I.; Milder, O.B.; Semionkin, V.A.; Malakheeva, L.I.; Prokopenko, P.G.

    2006-01-01

    Characterization of iron storage proteins in liver and spleen from normal chicken and chicken with lymphoid leukemia in comparison with human liver ferritin were considered by Moessbauer spectroscopy (preliminary results). Small differences in Moessbauer hyperfine parameters for both normal and lymphoid leukemia chicken liver and spleen were observed. The value of quadrupole splitting for human liver ferritin was higher than those for chicken tissues. A decrease of iron content in lymphoid leukemia chicken tissues was also found, however, the reason of this fact (pathology or feeding) was not clear yet. (author)

  18. Intestinal absorbtion from therapeutic iron doses

    International Nuclear Information System (INIS)

    Werner, E.

    1977-01-01

    On a total of 105 persons with normal iron stores, iron depletion, and iron deficiency the intestinal absorption from therapeutic iron doses (100 mg Fe and 50 mg Fe as ferrous glycocoll sulphate) of a special galenic form was measured. The measurements were performed by means of a whole-body counter and preparations labelled with radio iron ( 59 Fe). Mean values of absorption rates from 100 mg Fe in healthy males were 5.0% and in healthy females 5.6% whereas in latent iron deficiency and in iron deficiency anemia mean values of 10% and 13% were obtained, respectively. The maximum absorption rate of 20 to 25% is reached already in the late stage of latent iron deficiency. Advancing severeness of iron deficiency is not followed by an increase of iron absorption. Investigations an 21 persons showed no significant difference between absorption rates of the galenic preparations used when administered orally before or after breakfast, respectively. (orig.) [de

  19. Iron Isotope Fractionation in Microbial and Non-Biological Precipitates, and the Human Body

    Science.gov (United States)

    von Blanckenburg, F.; Boettcher, M. E.; Hofmann, B.; Walczyk, T.

    2001-12-01

    We have investigated biotic and abiotic stable iron isotope fractionation pathways in experiments, the low-T natural environment, and the human body. Fe samples were analysed using a Nu Plasma Multicollector ICP-MS. All measured samples plot on the theoretically predicted exponential fractionation line in the Delta57Fe versus Delta56Fe space, demonstrating absence of ArN or ArO interferences. An experimental calibration of Fe isotope fractionation during abiotic formation of iron (III) oxyhydroxide and iron(II) minerals from aqueous solution resulted in significant differences: (a) During fast precipitation of FeOOH during alkalization of a Fe(III)Cl3 solution at room temperature the solid is only slightly enriched by about 0.1permil in 57Fe compared to the solution. (b) Slow precipitation of akaganeite (beta-FeOOH) from aqueous Fe(III)Cl3 solution leads to a depletion of 57Fe by about -2.2permil in the solid phase without a significant influence of temperature. (c) Precipitation of FeOOH during oxidation of aqueous Fe(II) solutions by oxygen yields an enrichment of up to 4.8permil in 57Fe in the solid phase. (d) Iron(II) carbonate precipitation between 20 and 60C leads to an almost negligible depletion in 57Fe compared to aqueous ferrous ions. Interpretation: Large enrichment of the heavy isotope is observed where Fe is oxidised, whereas small to interme-diate depletions of heavy Fe isotopes occur upon forma-tion of Fe-minerals without change in redox state. Addi-tionally, kinetic effects, the speciation of the aqueous solution, or the effect of crystal structures may have to be considered. Biotic isotope fractionation by microorganisms was investigated at two field sites. In a Fe mine (Gonzen, Switzerland), Fe-precipitating microbes (Gallionella ferrugina and Leptohrix ochtraceae) have formed Fe(III)-oxyhydroxides that are ca. 0.6permil heavier in Delta57Fe than the Fe-rich parent solutions. At Cady Mts, California, filamentous fabrics of goethite, thought to

  20. ANALYSIS ABSORPTION CAPACITY OF EUROPEAN FUNDS UNDER THE OPERATIONAL PROGRAMME HUMAN RESOURCES DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    DANIELA FLORESCU

    2013-10-01

    Full Text Available One of the main goals of the European Union is the economic progress. In the last 50 years, and especially beginning with the ‘80s, remarkable efforts have been made for removing the borders between the EU national economies and for creating a unique market where goods, persons, capital and services could move freely. Commercial interchanges between UE states have significantly grown and at the same time EU has become a global commercial force. EU’s goal is to become the most dynamic economy based on global recognition. This implies a significant investment in research, education and forming, which allows the population to have access to this new information. This research work displays diverse aspects concerning the Romania’s ability draw of irredeemable funds in period 2007 – 2013, focusing on human capital development activity. Today, the problem absorptions are no longer able to develop projects, that knowing a significant improvement but the stage of implementation and funding.

  1. Dermal absorption and disposition of musk ambrette, musk ketone and musk xylene in human subjects.

    Science.gov (United States)

    Hawkins, David R; Elsom, Lionel F; Kirkpatrick, David; Ford, Richard A; Api, Anne Marie

    2002-05-28

    Musk ambrette, musk ketone and musk xylene have a long history of use as fragrance ingredients, although musk ambrette is no longer used in fragrances. As part of the review of the safety of these uses, it is important to consider the systemic exposure that results from these uses. Since the primary route of exposure to fragrances is on the skin, dermal doses of carbon-14 labelled musk ambrette, musk ketone and musk xylene were applied to the backs (100 cm2) of healthy human volunteers (two to three subjects) at a nominal dose level of 10-20 microg/cm2 and excess material removed at 6 h. Means of 2.0% musk ambrette, 0.5% musk ketone and 0.3% musk xylene were absorbed based on the amounts excreted in urine and faeces during 5 days. Most of the material was excreted in the urine with less than 10% of the amount excreted being found in faeces. No radioactivity was detected in any plasma sample, consistent with low absorption, and no radioactivity was detected (<0.02% dose) in skin strips taken at 120 h. Analysis of urine samples indicated that all three compounds were excreted mainly as single glucuronide conjugates. The aglycones were chromatographically different, but of similar polarity, to the major rat metabolites excreted in bile also as glucuronides.

  2. Rare earth analysis in human biological samples by atomic absorption using electrothermal atomization

    International Nuclear Information System (INIS)

    Citron, I.M.; Holtzman, R.B.; Leiman, J.

    1982-01-01

    The determination of Sc and seven rare earth elements, Nd, Sm, Dy, Ho, Eu, Tm, and Yb, in biological samplesby atomic absorption spectrophotometric analysis (AAS) using electrothermal atomization in a pyrolytic graphite tube is shown to be rapid, precise and accurate. The technique utilizes the method of standard additions and linear regression analysis to determine results from peak area data. Inter-elemental interferences are negligible. The elements found sensitive enough for this type of analysis are, in order of decreasing sensitivity, Yb, Eu, Tm, Dy, Sc, Ho, Sm and Nd. The determination in these types of materials of Gd and elements less sensitive to AAS detection than Gd does not appear to be feasible. Results are presented on the concentrations of these elements in 41 samples from human subjects, cows and vegetables with normal environmental exposure to the rare earth elements. The composite percent mean deviation in peak-area readings for all samples and all elements examined was 4%. The mean standard error in the results among samples was about 6.5%

  3. Current understanding of iron homeostasis.

    Science.gov (United States)

    Anderson, Gregory J; Frazer, David M

    2017-12-01

    Iron is an essential trace element, but it is also toxic in excess, and thus mammals have developed elegant mechanisms for keeping both cellular and whole-body iron concentrations within the optimal physiologic range. In the diet, iron is either sequestered within heme or in various nonheme forms. Although the absorption of heme iron is poorly understood, nonheme iron is transported across the apical membrane of the intestinal enterocyte by divalent metal-ion transporter 1 (DMT1) and is exported into the circulation via ferroportin 1 (FPN1). Newly absorbed iron binds to plasma transferrin and is distributed around the body to sites of utilization with the erythroid marrow having particularly high iron requirements. Iron-loaded transferrin binds to transferrin receptor 1 on the surface of most body cells, and after endocytosis of the complex, iron enters the cytoplasm via DMT1 in the endosomal membrane. This iron can be used for metabolic functions, stored within cytosolic ferritin, or exported from the cell via FPN1. Cellular iron concentrations are modulated by the iron regulatory proteins (IRPs) IRP1 and IRP2. At the whole-body level, dietary iron absorption and iron export from the tissues into the plasma are regulated by the liver-derived peptide hepcidin. When tissue iron demands are high, hepcidin concentrations are low and vice versa. Too little or too much iron can have important clinical consequences. Most iron deficiency reflects an inadequate supply of iron in the diet, whereas iron excess is usually associated with hereditary disorders. These disorders include various forms of hemochromatosis, which are characterized by inadequate hepcidin production and, thus, increased dietary iron intake, and iron-loading anemias whereby both increased iron absorption and transfusion therapy contribute to the iron overload. Despite major recent advances, much remains to be learned about iron physiology and pathophysiology. © 2017 American Society for Nutrition.

  4. Effectiveness of hand washing on the removal of iron oxide nanoparticles from human skin ex vivo.

    Science.gov (United States)

    Lewinski, Nastassja A; Berthet, Aurélie; Maurizi, Lionel; Eisenbeis, Antoine; Hopf, Nancy B

    2017-08-01

    In this study, the effectiveness of washing with soap and water in removing nanoparticles from exposed skin was investigated. Dry, nanoscale hematite (α-Fe 2 O 3 ) or maghemite (γ-Fe 2 O 3 ) powder, with primary particle diameters between 20-30 nm, were applied to two samples each of fresh and frozen ex vivo human skin in two independent experiments. The permeation of nanoparticles through skin, and the removal of nanoparticles after washing with soap and water were investigated. Bare iron oxide nanoparticles remained primarily on the surface of the skin, without penetrating beyond the stratum corneum. Skin exposed to iron oxide nanoparticles for 1 and 20 hr resulted in removal of 85% and 90%, respectively, of the original dose after washing. In the event of dermal exposure to chemicals, removal is essential to avoid potential local irritation or permeation across skin. Although manufactured at an industrial scale and used extensively in laboratory experiments, limited data are available on the removal of engineered nanoparticles after skin contact. Our finding raises questions about the potential consequences of nanoparticles remaining on the skin and whether alternative washing methods should be proposed. Further studies on skin decontamination beyond use of soap and water are needed to improve the understanding of the potential health consequences of dermal exposure to nanoparticles.

  5. Effect of absorbable and nonabsorbable sugars on intestinal calcium absorption in humans

    International Nuclear Information System (INIS)

    Griessen, M.; Speich, P.V.; Infante, F.; Bartholdi, P.; Cochet, B.; Donath, A.; Courvoisier, B.; Bonjour, J.P.

    1989-01-01

    The effects of glucose, galactose, and lactitol on intestinal calcium absorption and gastric emptying were studied in 9, 8, and 20 healthy subjects, respectively. Calcium absorption was measured by using a double-isotope technique and the kinetic parameters were obtained by a deconvolution method. The gastric emptying rate was determined with /sup 99m/Tc-diethylenetriaminepentaacetic acid and was expressed as the half-time of the emptying curve. Each subject was studied under two conditions: (a) with calcium alone and (b) with calcium plus sugar. Glucose and galactose increased the calcium mean transit time and improved the total fractional calcium absorption by 30% (p less than 0.02). Lactitol decreased the mean rate of absorption (p less than 0.001) and reduced the total fractional calcium absorption by 15% (p less than 0.001). The gastric emptying rate did not appear to influence directly the kinetic parameters of calcium absorption. These results show that both glucose and galactose exert the same stimulatory effect as lactose on calcium absorption in subjects with normal lactase whereas lactitol mimics the effects of lactose in lactase-deficient patients. Thus the absorbability of sugars determines their effect on calcium absorption

  6. Iron environment in ferritin with large amounts of phosphate, from Azotobacter vinelandii and horse spleen, analyzed using Extended X-ray Absorption fine Structure (EXAFS)

    International Nuclear Information System (INIS)

    Rohrer, J.S.; Islam, Q.T.; Sayes, D.E.; Theil, E.C.; Watt, G.D.

    1990-01-01

    The iron core of proteins in the ferritin family displays structural variations that includes phosphate content was well as the number and the degree of ordering of the iron atoms. Earlier studies had shown that ferritin iron cores naturally high in phosphate, e.g., Azotobacter vinelandii (AV) ferritin had decreased long-range order. Here, the influence of phosphate on the local structure around iron in ferritin cores is reported, comparing the EXAFS of AV ferritin, reconstituted ferritin and native horse spleen ferritin. In contrast, when the phosphate content was high in AV ferritin and horse spleen ferritin reconstituted with phosphate, the average iron atom had five to six phosphorus neighbors at 3.17 angstrom. Moreover, the number of detectable iron neighbors was lower when phosphate was high or present during reconstitution and the interatomic distance was longer indicating that some phosphate bridges neighboring iron atoms. However, the decrease in the number of detectable iron-iron neighbors compared to HSF and the higher number of Fe-P interactions relative to Fe-Fe interactions suggest that some phosphate ligands were chain termini, or blocked crystal growth, and/or introduced defects which contributed both to the long-range disorder and to altered redox properties previously observed in AV ferritin

  7. The potential of immobilized artificial membrane chromatography to predict human oral absorption.

    Science.gov (United States)

    Tsopelas, Fotios; Vallianatou, Theodosia; Tsantili-Kakoulidou, Anna

    2016-01-01

    The potential of immobilized artificial membrane (IAM) chromatography to estimate human oral absorption (%HOA) was investigated. For this purpose, retention indices on IAM stationary phases reported previously by our group or measured by other authors under similar conditions were used to model %HOA data, compiled from literature sources. Considering the pH gradient in gastrointestinal tract, the highest logkw(IAM) values were considered, obtained either at pH7.4 or 5.5, defined as logkw(IAM)(best). Non linear models were established upon introduction of additional parameters and after exclusion of drugs which are substrates either to efflux or uptake transporters. The best model included Abraham's hydrogen-bond acidity parameter, molecular weight as well as the positively and negatively charged molecular fractions. For reasons of comparison between IAM chromatography and traditional lipophilicity, corresponding models were derived by replacing IAM retention factors with octanol-water distribution coefficients (logD). An overexpression of electrostatic interactions with phosphate anions was observed in the case of IAM retention as expressed by the negative contribution of the positively charged fraction F(+). The same parameter is statistically significant also in the logD model, but with a positive sign, indicating the attraction of basic drugs in the negatively charged inner membrane. To validate the obtained models a blind test set of 22 structurally diverse drugs was used, whose logkw(IAM)(best) values were determined and analyzed in the present study under similar conditions. IAM retention factors were further compared with MDCK cell lines permeability data taken from literature for a set of validation drugs. The overexpression of electrostatic interactions with phosphate anions on IAM surface was also evident in respect to MDCK permeability. In contrast to the clear classification between drugs with high and poor (or intermediate) absorption provided by MDCK

  8. Development of iron homeostasis in infants and young children.

    Science.gov (United States)

    Lönnerdal, Bo

    2017-12-01

    Healthy, term, breastfed infants usually have adequate iron stores that, together with the small amount of iron that is contributed by breast milk, make them iron sufficient until ≥6 mo of age. The appropriate concentration of iron in infant formula to achieve iron sufficiency is more controversial. Infants who are fed formula with varying concentrations of iron generally achieve sufficiency with iron concentrations of 2 mg/L (i.e., with iron status that is similar to that of breastfed infants at 6 mo of age). Regardless of the feeding choice, infants' capacity to regulate iron homeostasis is important but less well understood than the regulation of iron absorption in adults, which is inverse to iron status and strongly upregulated or downregulated. Infants who were given daily iron drops compared with a placebo from 4 to 6 mo of age had similar increases in hemoglobin concentrations. In addition, isotope studies have shown no difference in iron absorption between infants with high or low hemoglobin concentrations at 6 mo of age. Together, these findings suggest a lack of homeostatic regulation of iron homeostasis in young infants. However, at 9 mo of age, homeostatic regulatory capacity has developed although, to our knowledge, its extent is not known. Studies in suckling rat pups showed similar results with no capacity to regulate iron homeostasis at 10 d of age when fully nursing, but such capacity occurred at 20 d of age when pups were partially weaned. The major iron transporters in the small intestine divalent metal-ion transporter 1 (DMT1) and ferroportin were not affected by pup iron status at 10 d of age but were strongly affected by iron status at 20 d of age. Thus, mechanisms that regulate iron homeostasis are developed at the time of weaning. Overall, studies in human infants and experimental animals suggest that iron homeostasis is absent or limited early in infancy largely because of a lack of regulation of the iron transporters DMT1 and ferroportin

  9. Fractionation separation of human plasma proteins using HPLC with a homemade iron porphyrin based monolithic column.

    Science.gov (United States)

    Zhang, Doudou; Zhao, Yu; Lan, Dandan; Pang, Xiaomin; Bai, Ligai; Liu, Haiyan; Yan, Hongyuan

    2017-11-15

    In this work a polymer monolithic column was fabricated within the confines of a stainless steel column (50×4.6mm i.d.) via radical polymerization by using iron porphyrin and butyl methacrylate as co-monomers, ethylene glycol dimethacrylate as crosslinking agent, ethylene glycol, isopropyl alcohol and N, N-dimethylformamide as tri-porogens, benzoyl peroxide and N,N-dimethylaniline as initiators. The resulting monolithic column was characterized by elemental analysis, scanning electron microscopy, nitrogen adsorption BET surface area, and mercury intrusion porosimetry, respectively. Results showed that the homemade monolith occupied relatively uniform pore structure, low back pressure, and enhanced selectivity for proteins in complex bio-samples. The present work described a simple and efficient method for "fractionation separation" of human plasma proteins, and it is a promising separation method for complex bio-samples in proteomic research. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. 24-hour human urine and serum profiles of bisphenol A: Evidence against sublingual absorption following ingestion in soup

    Energy Technology Data Exchange (ETDEWEB)

    Teeguarden, Justin G., E-mail: jt@pnl.gov [Health Effects and Exposure Science, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 93771 (United States); Twaddle, Nathan C., E-mail: nathan.twaddle@fda.hhs.gov [Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Churchwell, Mona I., E-mail: mona.churchwell@fda.hhs.gov [Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Yang, Xiaoxia, E-mail: xiaoxia.yang@fda.hhs.gov [Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Fisher, Jeffrey W., E-mail: jeffrey.fisher@fda.hhs.gov [Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Seryak, Liesel M., E-mail: seryak.2@osu.edu [Division of Epidemiology, College of Public Health, The Ohio State University, Columbus, OH 43210 (United States); Doerge, Daniel R., E-mail: daniel.doerge@fda.hhs.gov [Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States)

    2015-10-15

    Extensive first-pass metabolism of ingested bisphenol A (BPA) in the gastro-intestinal tract and liver restricts blood concentrations of bioactive BPA to < 1% of total BPA in humans and non-human primates. Absorption of ingested BPA through non-metabolizing tissues of the oral cavity, recently demonstrated in dogs, could lead to the higher serum BPA concentrations reported in some human biomonitoring studies. We hypothesized that the extensive interaction with the oral mucosa by a liquid matrix, like soup, relative to solid food or capsules, might enhance absorption through non-metabolizing oral cavity tissues in humans, producing higher bioavailability and higher serum BPA concentrations. Concurrent serum and urine concentrations of d6-BPA, and its glucuronide and sulfate conjugates, were measured over a 24 hour period in 10 adult male volunteers following ingestion of 30 μg d6-BPA/kg body weight in soup. Absorption of d6-BPA was rapid (t{sub 1/2} = 0.45 h) and elimination of the administered dose was complete 24 h post-ingestion, evidence against any tissue depot for BPA. The maximum serum d6-BPA concentration was 0.43 nM at 1.6 h after administration and represented < 0.3% of total d6-BPA. Pharmacokinetic parameters, pharmacokinetic model simulations, and the significantly faster appearance half-life of d6-BPA-glucuronide compared to d6-BPA (0.29 h vs 0.45 h) were evidence against meaningful absorption of BPA in humans through any non-metabolizing tissue (< 1%). This study confirms that typical exposure to BPA in food produces picomolar to subpicomolar serum BPA concentrations in humans, not nM concentrations reported in some biomonitoring studies.

  11. 24-hour human urine and serum profiles of bisphenol A: Evidence against sublingual absorption following ingestion in soup.

    Science.gov (United States)

    Teeguarden, Justin G; Twaddle, Nathan C; Churchwell, Mona I; Yang, Xiaoxia; Fisher, Jeffrey W; Seryak, Liesel M; Doerge, Daniel R

    2015-10-15

    Extensive first-pass metabolism of ingested bisphenol A (BPA) in the gastro-intestinal tract and liver restricts blood concentrations of bioactive BPA to <1% of total BPA in humans and non-human primates. Absorption of ingested BPA through non-metabolizing tissues of the oral cavity, recently demonstrated in dogs, could lead to the higher serum BPA concentrations reported in some human biomonitoring studies. We hypothesized that the extensive interaction with the oral mucosa by a liquid matrix, like soup, relative to solid food or capsules, might enhance absorption through non-metabolizing oral cavity tissues in humans, producing higher bioavailability and higher serum BPA concentrations. Concurrent serum and urine concentrations of d6-BPA, and its glucuronide and sulfate conjugates, were measured over a 24hour period in 10 adult male volunteers following ingestion of 30μg d6-BPA/kg body weight in soup. Absorption of d6-BPA was rapid (t1/2=0.45h) and elimination of the administered dose was complete 24h post-ingestion, evidence against any tissue depot for BPA. The maximum serum d6-BPA concentration was 0.43nM at 1.6h after administration and represented <0.3% of total d6-BPA. Pharmacokinetic parameters, pharmacokinetic model simulations, and the significantly faster appearance half-life of d6-BPA-glucuronide compared to d6-BPA (0.29h vs 0.45h) were evidence against meaningful absorption of BPA in humans through any non-metabolizing tissue (<1%). This study confirms that typical exposure to BPA in food produces picomolar to subpicomolar serum BPA concentrations in humans, not nM concentrations reported in some biomonitoring studies. Published by Elsevier Inc.

  12. 24-hour human urine and serum profiles of bisphenol A: Evidence against sublingual absorption following ingestion in soup

    International Nuclear Information System (INIS)

    Teeguarden, Justin G.; Twaddle, Nathan C.; Churchwell, Mona I.; Yang, Xiaoxia; Fisher, Jeffrey W.; Seryak, Liesel M.; Doerge, Daniel R.

    2015-01-01

    Extensive first-pass metabolism of ingested bisphenol A (BPA) in the gastro-intestinal tract and liver restricts blood concentrations of bioactive BPA to < 1% of total BPA in humans and non-human primates. Absorption of ingested BPA through non-metabolizing tissues of the oral cavity, recently demonstrated in dogs, could lead to the higher serum BPA concentrations reported in some human biomonitoring studies. We hypothesized that the extensive interaction with the oral mucosa by a liquid matrix, like soup, relative to solid food or capsules, might enhance absorption through non-metabolizing oral cavity tissues in humans, producing higher bioavailability and higher serum BPA concentrations. Concurrent serum and urine concentrations of d6-BPA, and its glucuronide and sulfate conjugates, were measured over a 24 hour period in 10 adult male volunteers following ingestion of 30 μg d6-BPA/kg body weight in soup. Absorption of d6-BPA was rapid (t 1/2 = 0.45 h) and elimination of the administered dose was complete 24 h post-ingestion, evidence against any tissue depot for BPA. The maximum serum d6-BPA concentration was 0.43 nM at 1.6 h after administration and represented < 0.3% of total d6-BPA. Pharmacokinetic parameters, pharmacokinetic model simulations, and the significantly faster appearance half-life of d6-BPA-glucuronide compared to d6-BPA (0.29 h vs 0.45 h) were evidence against meaningful absorption of BPA in humans through any non-metabolizing tissue (< 1%). This study confirms that typical exposure to BPA in food produces picomolar to subpicomolar serum BPA concentrations in humans, not nM concentrations reported in some biomonitoring studies.

  13. Energy dispersive x-ray fluorescence spectrometric determination of phosphorus, calcium, iron, zinc, and strontium in human bones

    International Nuclear Information System (INIS)

    Ohta, Akishige; Matsubayashi, Takashi; Itoman, Moritoshi

    1981-01-01

    Phosphorus, calcium, iron, zinc and strontium in a human bone extracted by surgery were determined by energy dispersive X-ray fluorescence spectrometry. The bone was decomposed with nitric acid, then diluted with water. A specific quantity of the solution was naturally dried on polyethylene film, and subjected to X-ray analysis. For determining the calibration curves in a mixture of phosphorus, calcium, iron, zinc and strontium, for the analysis of phosphorus and calcium, germanium was used as the secondary target and aluminum as the filter; and for the analysis of iron, zinc and strontium, molybdenum and molybdenum-aluminum were used, respectively. Consequently, the calibration curves were able to be obtained with high precision in the ranges from 5 to 500 μg of phosphorus, from 1 to 50 μg of calcium and from 0.1 to 1.0 μg of iron, zinc and strontium. In this way, in 1 mg of the human bone by wet weight, phosphorus, calcium, iron, zinc and strontium were able to be determined. (J.P.N.)

  14. The N-terminal domain of human DNA helicase Rtel1 contains a redox active iron-sulfur cluster.

    Science.gov (United States)

    Landry, Aaron P; Ding, Huangen

    2014-01-01

    Human telomere length regulator Rtel1 is a superfamily II DNA helicase and is essential for maintaining proper length of telomeres in chromosomes. Here we report that the N-terminal domain of human Rtel1 (RtelN) expressed in Escherichia coli cells produces a protein that contains a redox active iron-sulfur cluster with the redox midpoint potential of -248 ± 10 mV (pH 8.0). The iron-sulfur cluster in RtelN is sensitive to hydrogen peroxide and nitric oxide, indicating that reactive oxygen/nitrogen species may modulate the DNA helicase activity of Rtel1 via modification of its iron-sulfur cluster. Purified RtelN retains a weak binding affinity for the single-stranded (ss) and double-stranded (ds) DNA in vitro. However, modification of the iron-sulfur cluster by hydrogen peroxide or nitric oxide does not significantly affect the DNA binding activity of RtelN, suggesting that the iron-sulfur cluster is not directly involved in the DNA interaction in the N-terminal domain of Rtel1.

  15. The N-Terminal Domain of Human DNA Helicase Rtel1 Contains a Redox Active Iron-Sulfur Cluster

    Directory of Open Access Journals (Sweden)

    Aaron P. Landry

    2014-01-01

    Full Text Available Human telomere length regulator Rtel1 is a superfamily II DNA helicase and is essential for maintaining proper length of telomeres in chromosomes. Here we report that the N-terminal domain of human Rtel1 (RtelN expressed in Escherichia coli cells produces a protein that contains a redox active iron-sulfur cluster with the redox midpoint potential of −248 ± 10 mV (pH 8.0. The iron-sulfur cluster in RtelN is sensitive to hydrogen peroxide and nitric oxide, indicating that reactive oxygen/nitrogen species may modulate the DNA helicase activity of Rtel1 via modification of its iron-sulfur cluster. Purified RtelN retains a weak binding affinity for the single-stranded (ss and double-stranded (ds DNA in vitro. However, modification of the iron-sulfur cluster by hydrogen peroxide or nitric oxide does not significantly affect the DNA binding activity of RtelN, suggesting that the iron-sulfur cluster is not directly involved in the DNA interaction in the N-terminal domain of Rtel1.

  16. A photo-oxidation procedure using UV radiation/H{sub 2}O{sub 2} for decomposition of wine samples - Determination of iron and manganese content by flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Walter N.L. dos [Departamento de Ciencias Exatas e da Terra, Universidade do Estado da Bahia, Salvador, Bahia (Brazil); Universidade Federal da Bahia, Instituto de Quimica, Campus Ondina, Salvador, Bahia, 40170-290 Brazil (Brazil)], E-mail: wlopes@uneb.br; Brandao, Geovani C.; Portugal, Lindomar A.; David, Jorge M.; Ferreira, Sergio L.C. [Universidade Federal da Bahia, Instituto de Quimica, Campus Ondina, Salvador, Bahia, 40170-290 Brazil (Brazil)

    2009-06-15

    This paper proposes the use of photo-oxidation with UV radiation/H{sub 2}O{sub 2} as sample pretreatment for the determination of iron and manganese in wines by flame atomic absorption spectrometry (FAAS). The optimization involved the study of the following variables: pH and concentration of buffer solution, concentrated hydrogen peroxide volume and irradiation time. The evaluation of sample degradation was monitored by measuring the absorbance at the maximum wavelength of red wine (530 nm). Using the experimental conditions established during the optimization (irradiation time of 30 min, oxidant volume of 2.5 mL, pH 10, and a buffer concentration of 0.15 mol L{sup - 1}), this procedure allows the determination of iron and manganese with limits of detection of 30 and 22 {mu}g L{sup - 1}, respectively, for a 5 mL volume of digested sample. The precision levels, expressed as relative standard deviation (RSD), were 2.8% and 0.65% for iron and 2.7% and 0.54% for manganese for concentrations of 0.5 and 2.0 mg L{sup - 1}, respectively. Addition/recovery tests for evaluation of the accuracy were in the ranges of 90%-111% and 95%-107% for iron and manganese, respectively. This digestion procedure has been applied for the determination of iron and manganese in six wine samples. The concentrations varied from 1.58 to 2.77 mg L{sup - 1} for iron and from 1.30 to 1.91 mg L{sup - 1} for manganese. The results were compared with those obtained by an acid digestion procedure and determination of the elements by FAAS. There was no significant difference between the results obtained by the two methods based on a paired t-test (at 95% confidence level)

  17. Association of Maternal Diet With Zinc, Copper, and Iron Concentrations in Transitional Human Milk Produced by Korean Mothers

    Science.gov (United States)

    Kim, Ji-Myung; Lee, Ji-Eun; Cho, Mi Sook; Kang, Bong Soo; Choi, Hyeon

    2016-01-01

    The aims of this study were to evaluate zinc, copper, and iron concentrations in the transitory milk of Korean lactating mothers and to investigate the relationship between these concentrations and maternal diet. Human milk samples were collected between 5 and 15 days postpartum from 96 healthy, lactating mothers in postpartum care centers in Seoul, Korea. Dietary intake during lactation was determined based on a 3-day dietary record. The mean zinc, copper, and iron concentrations in the human milk samples collected were 3.88 ± 1.74 mg/L, 0.69 ± 0.25 mg/L, and 5.85 ± 8.53 mg/L, respectively. The mothers who consumed alcoholic beverages during pregnancy had tended to have lower concentrations of zinc and copper, as well as significantly lower concentrations of iron, in their milk (p < 0.047). In contrast, the mothers who took daily supplements had much higher iron concentrations in their milk (p = 0.002). Dietary intakes of zinc, copper, and iron during lactation did not affect the concentrations of zinc, copper, and iron in the milk samples analyzed. Intakes of vitamin C, selenium, and iodine were associated with the concentration of copper in the milk samples analyzed, and consumption of food categorized as 'meat and meat products' was positively associated with the concentration of zinc. Consumption of rice was the top contributor to the concentrations of all three minerals. In conclusion, associations between maternal diet and nutrient concentrations in transitory human milk can provide useful information, particularly in regard to infant growth. PMID:26839873

  18. Narrative absorption

    DEFF Research Database (Denmark)

    Narrative Absorption brings together research from the social sciences and Humanities to solve a number of mysteries: Most of us will have had those moments, of being totally absorbed in a book, a movie, or computer game. Typically we do not have any idea about how we ended up in such a state. No...

  19. Analysis of Intra- and Intersubject Variability in Oral Drug Absorption in Human Bioequivalence Studies of 113 Generic Products.

    Science.gov (United States)

    Sugihara, Masahisa; Takeuchi, Susumu; Sugita, Masaru; Higaki, Kazutaka; Kataoka, Makoto; Yamashita, Shinji

    2015-12-07

    In this study, the data of 113 human bioequivalence (BE) studies of immediate release (IR) formulations of 74 active pharmaceutical ingredients (APIs) conducted at Sawai Pharmaceutical Co., Ltd., was analyzed to understand the factors affecting intra- and intersubject variabilities in oral drug absorption. The ANOVA CV (%) calculated from area under the time-concentration curve (AUC) in each BE study was used as an index of intrasubject variability (Vintra), and the relative standard deviation (%) in AUC was used as that of intersubject variability (Vinter). Although no significant correlation was observed between Vintra and Vinter of all drugs, Vintra of class 3 drugs was found to increase in association with a decrease in drug permeability (P(eff)). Since the absorption of class 3 drugs was rate-limited by the permeability, it was suggested that, for such drugs, the low P(eff) might be a risk factor to cause a large intrasubject variability. To consider the impact of poor water solubility on the variability in BE study, a parameter of P(eff)/Do (Do; dose number) was defined to discriminate the solubility-limited and dissolution-rate-limited absorption of class 2 drugs. It was found that the class 2 drugs with a solubility-limited absorption (P(eff)/Do high intrasubject variability. Furthermore, as a reason for high intra- or intersubject variability in AUC for class 1 drugs, effects of drug metabolizing enzymes were investigated. It was demonstrated that intrasubject variability was high for drugs metabolized by CYP3A4 while intersubject variability was high for drugs metabolized by CYP2D6. For CYP3A4 substrate drugs, the Km value showed the significant relation with Vintra, indicating that the affinity to the enzyme can be a parameter to predict the risk of high intrasubject variability. In conclusion, by analyzing the in house data of human BE study, low permeability, solubility-limited absorption, and high affinity to CYP3A4 are identified as risk factors for

  20. Architecture of the Human Mitochondrial Iron-Sulfur Cluster Assembly Machinery*

    Science.gov (United States)

    Gakh, Oleksandr; Ranatunga, Wasantha; Smith, Douglas Y.; Ahlgren, Eva-Christina; Al-Karadaghi, Salam; Thompson, James R.; Isaya, Grazia

    2016-01-01

    Fe-S clusters, essential cofactors needed for the activity of many different enzymes, are assembled by conserved protein machineries inside bacteria and mitochondria. As the architecture of the human machinery remains undefined, we co-expressed in Escherichia coli the following four proteins involved in the initial step of Fe-S cluster synthesis: FXN42–210 (iron donor); [NFS1]·[ISD11] (sulfur donor); and ISCU (scaffold upon which new clusters are assembled). We purified a stable, active complex consisting of all four proteins with 1:1:1:1 stoichiometry. Using negative staining transmission EM and single particle analysis, we obtained a three-dimensional model of the complex with ∼14 Å resolution. Molecular dynamics flexible fitting of protein structures docked into the EM map of the model revealed a [FXN42–210]24·[NFS1]24·[ISD11]24·[ISCU]24 complex, consistent with the measured 1:1:1:1 stoichiometry of its four components. The complex structure fulfills distance constraints obtained from chemical cross-linking of the complex at multiple recurring interfaces, involving hydrogen bonds, salt bridges, or hydrophobic interactions between conserved residues. The complex consists of a central roughly cubic [FXN42–210]24·[ISCU]24 sub-complex with one symmetric ISCU trimer bound on top of one symmetric FXN42–210 trimer at each of its eight vertices. Binding of 12 [NFS1]2·[ISD11]2 sub-complexes to the surface results in a globular macromolecule with a diameter of ∼15 nm and creates 24 Fe-S cluster assembly centers. The organization of each center recapitulates a previously proposed conserved mechanism for sulfur donation from NFS1 to ISCU and reveals, for the first time, a path for iron donation from FXN42–210 to ISCU. PMID:27519411

  1. Failure to label baboon milk intrinsically with iron

    International Nuclear Information System (INIS)

    Figueroa-Colon, R.; Elwell, J.H.; Jackson, E.; Osborne, J.W.; Fomon, S.J.

    1989-01-01

    The widely held belief that 50% of the iron in human milk is absorbed is based on studies that have used an extrinsic radioactive iron tag. To determine the validity of an extrinsic tag, it is necessary to label the milk intrinsically with one isotope and to compare absorption of this isotope with absorption of another isotope added as the extrinsic tag. We chose the baboon as a model and infused 59Fe intravenously. In each of three attempts we failed to label the milk intrinsically

  2. Safety implications of high-field MRI: actuation of endogenous magnetic iron oxides in the human body.

    Directory of Open Access Journals (Sweden)

    Jon Dobson

    Full Text Available Magnetic Resonance Imaging scanners have become ubiquitous in hospitals and high-field systems (greater than 3 Tesla are becoming increasingly common. In light of recent European Union moves to limit high-field exposure for those working with MRI scanners, we have evaluated the potential for detrimental cellular effects via nanomagnetic actuation of endogenous iron oxides in the body.Theoretical models and experimental data on the composition and magnetic properties of endogenous iron oxides in human tissue were used to analyze the forces on iron oxide particles.Results show that, even at 9.4 Tesla, forces on these particles are unlikely to disrupt normal cellular function via nanomagnetic actuation.

  3. Modification of the surface of superparamagnetic iron oxide nanoparticles to enable their safe application in humans.

    Science.gov (United States)

    Strehl, Cindy; Maurizi, Lionel; Gaber, Timo; Hoff, Paula; Broschard, Thomas; Poole, A Robin; Hofmann, Heinrich; Buttgereit, Frank

    Combined individually tailored methods for diagnosis and therapy (theragnostics) could be beneficial in destructive diseases, such as rheumatoid arthritis. Nanoparticles are promising candidates for theragnostics due to their excellent biocompatibility. Nanoparticle modifications, such as improved surface coating, are in development to meet various requirements, although safety concerns mean that modified nanoparticles require further review before their use in medical applications is permitted. We have previously demonstrated that iron oxide nanoparticles with amino-polyvinyl alcohol (a-PVA) adsorbed on their surfaces have the unwanted effect of increasing human immune cell cytokine secretion. We hypothesized that this immune response was caused by free-floating PVA. The aim of the present study was to prevent unwanted immune reactions by further surface modification of the a-PVA nanoparticles. After cross-linking of PVA to nanoparticles to produce PVA-grafted nanoparticles, and reduction of their zeta potential, the effects on cell viability and cytokine secretion were analyzed. PVA-grafted nanoparticles still stimulated elevated cytokine secretion from human immune cells; however, this was inhibited after reduction of the zeta potential. In conclusion, covalent cross-linking of PVA to nanoparticles and adjustment of the surface charge rendered them nontoxic to immune cells, nonimmunogenic, and potentially suitable for use as theragnostic agents.

  4. Isotope aided studies of the bioavailability of iron and zinc from human diets consumed in Peru

    International Nuclear Information System (INIS)

    Zavaleta, N.; Penny, M.; Berlanga, R.; Espinoza, R.; Lonnerdal, B.

    1992-01-01

    Iron deficiency can produce disturbances in physical and mental health, the most common sign of severe iron deficiency being anaemia. Iron deficiency anaemia can impair work capacity; learning capacity and result in changes in behaviour as well as compromise immunocompetence and causing less resistance to infections. In pregnancy, there is evidence that severe anaemia increases the risk of maternal morbidity and mortality as well as premature delivery. There is thus ample justification for attempting to implement programmes to combat iron deficiency in developing countries such as Peru. In order to determine the most appropriate intervention it is necessary to have data on the prevalence and severity of iron deficiency. The purpose of this study is to develop the necessary steps to implement a fortification programme to combat iron deficiency anaemia in Peru, targeted to pre-school children and pregnant women, who are the risk groups due to their increased requirements of this nutrient. 11 refs, 6 figs, 6 tabs

  5. Magnesium absorption in human subjects from leafy vegetables, intrinsically labeled with stable 26Mg

    International Nuclear Information System (INIS)

    Schwartz, R.; Spencer, H.; Welsh, J.J.

    1984-01-01

    Collards, turnip greens, leaf lettuce, and spinach, grown in nutrient solution so that their Mg content was 80 to 90% 26 Mg, were tested in ambulant male volunteers stabilized on a constant metabolic diet. The freeze-dried vegetables were incorporated in bran muffins in which the vegetables replaced part of the bran. Bran muffins without vegetables were consumed for breakfast each day. They were also used as a standard test meal to which the vegetable muffins were compared. All subjects participated in three consecutive isotope absorption tests: one of the standard test meal and two of the vegetables. The standard test was carried out after at least 30 days on the controlled diet. Subsequent tests of vegetables followed at 4-wk intervals. Each test meal contained 30 microCi 28 MgCl2 and 50 mg stable 26 Mg, the latter either as the intrinsic label of a test vegetable or as 26 MgCl 2 in solution taken with the standard bran muffins. Net absorption of both isotopes was measured to establish exchangeability and to determine relative Mg absorption from the vegetables. Exchangeability was 90% or higher from all meals tested. Relative Mg absorption was highest from collards and least from the standard test meal. Net absorption values ranged from 40 to 60%

  6. Fluid absorption related to ion transport in human airway epithelial spheroids

    DEFF Research Database (Denmark)

    Pedersen, P S; Holstein-Rathlou, N H; Larsen, P L

    1999-01-01

    , and amiloride inhibited both values. Fluid transport rates were calculated from repeated measurements of spheroid diameters. The results showed that 1) non-CF and CF spheroids absorbed fluid at identical rates (4.4 microl x cm(-2) x h(-1)), 2) amiloride inhibited fluid absorption to a lower residual level...... in non-CF than in CF spheroids, 3) Cl(-)-channel inhibitors increased fluid absorption in amiloride-treated non-CF spheroids to a level equal to that of amiloride-treated CF spheroids, 4) hydrochlorothiazide reduced the amiloride-insensitive fluid absorption in both non-CF and CF spheroids, and 5......) osmotic water permeabilities were equal in non-CF and CF spheroids ( approximately 27 x 10(-7) cm x s(-1) x atm(-1))....

  7. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... is blood loss during dialysis. People who have chronic kidney disease also often take other medicines—such as proton ... reduces iron absorption. Other treatments If you have chronic kidney disease and iron-deficiency anemia, your doctor may recommend ...

  8. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... Health and Human Development, we are investigating how best to treat premature newborns with low hemoglobin levels. ... are hoping to determine which iron supplements work best to treat iron-deficiency anemia in children who ...

  9. Iron supplements (image)

    Science.gov (United States)

    The mineral iron is an essential nutrient for humans because it is part of blood cells, which carry oxygen to all body cells. There is no conclusive evidence that iron supplements contribute to heart attacks.

  10. Isotope aided studies on the bioavailability of iron and zinc from human diets consumed in India

    International Nuclear Information System (INIS)

    Raghuramulu, N.; Das, P.; Prasad, P.

    1994-01-01

    Total iron, and zinc, in-vitro ionizable iron and soluble zinc were estimated by the chemical and extrinsic isotope tag methods for comparison in various foodstuffs as such, and after processing, and also in diets. It has been observed that the values got were more or less similar by both the procedures. The in-vitro ionizable iron in groundnut was low with low total iron as well. Total iron and ionizable iron were also estimated in commonly consumed breakfast preparations. The effect of tea on ionizable iron when taken along with breakfast was also investigated. It was found that different breakfast preparations varied narrowly with regards to total iron (4.6-7.2 mg) and percent ionizable iron (25%-33%). However, tea had a pronounced effect on ionizable iron resulting in inhibition to various extents. Total and soluble zinc were analyzed in green leafy vegetables and groundnut. Though the total zinc was low and similar in both foodstuffs, the percent soluble Zn was found to be high in green leafy vegetables as compared to groundnut. Tannin and ascorbic acid contents were estimated in a few foodstuffs. Tannin content in green leafy vegetables was found to be about 150 mg. Ascorbic acid concentration was high in cereals (except in rice) and whole pulses. The split pulses (dals) were found to be poor sources of ascorbic acid. Ionizable iron and soluble zinc were found to increase to various extents on processing. Germination was found to increase ascorbic acid, whereas it had no effect on tannin. (author). 4 figs, 8 tabs

  11. Prebiotics and the absorption of minerals: a review of experimental and human data

    Science.gov (United States)

    Dietary factors, including calcium and vitamin D intake, absorption, and status, lifestyle factors including physical activity, and genetics interact to determine peak bone mass. The current recommended dietary intake of calcium (adequate intake, AI) of 1300 mg/day in the United States for adolescen...

  12. New human milk fat substitutes from butterfat to improve fat absorption

    DEFF Research Database (Denmark)

    Li, Yanqi; Mu, Huiling; Andersen, Jens Enevold Thaulov

    2010-01-01

    , or (3) the reference oil without LCPUFA. The apparent fat absorption after intake of butterfat-based HMFS (95.9% +/- 1.8%) was significantly higher than the other two groups, indicating that much less calcium soap was formed after feeding butterfat-based HMFS. Calcium contents in urines and faeces from...

  13. Effect of room absorption on human vocal output in multitalker situations

    NARCIS (Netherlands)

    Nijs, L.; Saher, K.; Den Ouden, D.

    2008-01-01

    People increase their vocal output in noisy environments. This is known as the Lombard effect. The aim of the present study was to measure the effect as a function of the absorption coefficient. The noise source was generated by using other talkers in the room. A-weighted sound levels were measured

  14. Total calcium absorption is similar from infant formulas with and without prebiotics and exceeds that in human milk-fed infants

    Science.gov (United States)

    Our goal was to evaluate calcium absorption in infants fed a formula containing prebiotics (PF) and one without prebiotics (CF), and to compare calcium absorption from these formulas with a group of human milk-fed (HM) infants. A dual tracer stable isotope method was used to assess calcium absorptio...

  15. A comparison of physical properties, screening procedures and a human efficacy trial for predicting the bioavailability of commercial elemental iron powders used for food fortification

    NARCIS (Netherlands)

    Zimmermann, M.B.; Lynch, S.R.; Bothwell, T.

    2007-01-01

    Elemental iron powders are widely used to fortify staple foods. This paper summarizes physical and chemical measurements that were conducted to assess the bioavailability of these iron powders relative to ferrous sulfate, along with validation of these assessments from a study with human subjects.

  16. Iron metabolism in mynah birds (Gracula religiosa) resembles human hereditary haemochromatosis

    NARCIS (Netherlands)

    Mete, A; Hendriks, HG; Klaren, PHM; Dorrestein, GM; van Dijk, JE; Marx, JJM

    2003-01-01

    Iron overload is a very frequent finding in several animal species and a genetic predisposition is suggested. In one of the most commonly reported species with susceptibility for iron overload ( mynah bird), it was recently shown that the cause of this pathophysiology is high uptake and retention of

  17. Polymorphisms and mutations of human TMPRSS6 in iron deficiency anemia.

    NARCIS (Netherlands)

    Beutler, E.; Geet, C. Van; Loo, D.M.W.M. te; Gelbart, T.; Crain, K.; Truksa, J.; Lee, P.L.

    2010-01-01

    Male subjects with iron deficiency from the general population were examined for polymorphisms or sporadic mutations in TMPRSS6 to identify genetic risk factors for iron deficiency anemia. Three uncommon non-synonymous polymorphisms were identified, G228D, R446W, and V795I (allele frequencies

  18. Efficient internalization of silica-coated iron oxide nanoparticles of different sizes by primary human macrophages and dendritic cells

    International Nuclear Information System (INIS)

    Kunzmann, Andrea; Andersson, Britta; Vogt, Carmen; Feliu, Neus; Ye Fei; Gabrielsson, Susanne; Toprak, Muhammet S.; Buerki-Thurnherr, Tina; Laurent, Sophie; Vahter, Marie; Krug, Harald; Muhammed, Mamoun; Scheynius, Annika; Fadeel, Bengt

    2011-01-01

    Engineered nanoparticles are being considered for a wide range of biomedical applications, from magnetic resonance imaging to 'smart' drug delivery systems. The development of novel nanomaterials for biomedical applications must be accompanied by careful scrutiny of their biocompatibility. In this regard, particular attention should be paid to the possible interactions between nanoparticles and cells of the immune system, our primary defense system against foreign invasion. On the other hand, labeling of immune cells serves as an ideal tool for visualization, diagnosis or treatment of inflammatory processes, which requires the efficient internalization of the nanoparticles into the cells of interest. Here, we compare novel monodispersed silica-coated iron oxide nanoparticles with commercially available dextran-coated iron oxide nanoparticles. The silica-coated iron oxide nanoparticles displayed excellent magnetic properties. Furthermore, they were non-toxic to primary human monocyte-derived macrophages at all doses tested whereas dose-dependent toxicity of the smaller silica-coated nanoparticles (30 nm and 50 nm) was observed for primary monocyte-derived dendritic cells, but not for the similarly small dextran-coated iron oxide nanoparticles. No macrophage or dendritic cell secretion of pro-inflammatory cytokines was observed upon administration of nanoparticles. The silica-coated iron oxide nanoparticles were taken up to a significantly higher degree when compared to the dextran-coated nanoparticles, irrespective of size. Cellular internalization of the silica-coated nanoparticles was through an active, actin cytoskeleton-dependent process. We conclude that these novel silica-coated iron oxide nanoparticles are promising materials for medical imaging, cell tracking and other biomedical applications.

  19. The intestinal absorption of dietary cholesterol by hypercholesterolemic (type II) and normocholesterolemic humans.

    Science.gov (United States)

    Connor, W E; Lin, D S

    1974-04-01

    The incomplete absorption of dietary cholesterol may represent an adaptive intestinal barrier that prevents hypercholesterolemia. To explore this mechanism, we compared cholesterol absorption in 15 normocholesterolemic and 6 hypercholesterolemic (type II) subjects fed background cholesterol-free formula diets with 40% of calories as fat. Each test meal consisted of a breakfast into which was incorporated scrambled egg yolk containing 300-500 mg of cholesterol and [4-(14)C]cholesterol (3-22 muCi), either naturally incorporated into the yolk cholesterol by previous isotope injection into the laying hen or added in peanut oil to the yolk of the test breakfast. In some instances [1alpha-(3)H]cholesterol was the radioactive marker. The radioactivity of the fecal neutral sterol fraction was determined in daily stool samples for the next 7 days to provide an estimate of unabsorbed dietary cholesterol. The amount of absorbed and reexcreted labeled cholesterol proved negligible. Most unabsorbed dietary cholesterol appeared in the stool on the second or third day after the meal, and 95% or more was recovered in the stool by 6 days. Plasma specific activity curves were usually maximal at 48 h. Normal subjects absorbed 44.5+/-9.3 (SD) of the administered cholesterol (range 25.9-60.3). Hypercholesterolemics absorbed the same percentage of cholesterol as normals: 47.6+/-12.6% (range 29.3-67.3). Absorption was similar whether the radiolabeled cholesterol was added to egg yolk or naturally incorporated in it (42.1+/-9.3 vs. 48.9+/-9.8%). Six normal subjects were fed a cholesterol-free formula for 4 wk, and then different amounts of cholesterol (110-610 mg/day) were added for another 4 wk. At the end of each period, single test meals containing either 110, 310, or 610 mg of cholesterol and [1alpha-(3)H]cholesterol were administered. Cholesterol absorption was 42.3+/-6.0% and 45.4+/-8.3% for the two dietary periods, respectively. The absolute cholesterol absorption was linearly

  20. The cytotoxicity evaluation of magnetic iron oxide nanoparticles on human aortic endothelial cells

    Science.gov (United States)

    Ge, Gaoyuan; Wu, Hengfang; Xiong, Fei; Zhang, Yu; Guo, Zhirui; Bian, Zhiping; Xu, Jindan; Gu, Chunrong; Gu, Ning; Chen, Xiangjian; Yang, Di

    2013-05-01

    One major obstacle for successful application of nanoparticles in medicine is its potential nanotoxicity on the environment and human health. In this study, we evaluated the cytotoxicity effect of dimercaptosuccinic acid-coated iron oxide (DMSA-Fe2O3) using cultured human aortic endothelial cells (HAECs). Our results showed that DMSA-Fe2O3 in the culture medium could be absorbed into HAECs, and dispersed in the cytoplasm. The cytotoxicity effect of DMSA-Fe2O3 on HAECs was dose-dependent, and the concentrations no more than 0.02 mg/ml had little toxic effect which were revealed by tetrazolium dye assay. Meanwhile, the cell injury biomarker, lactate dehydrogenase, was not significantly higher than that from control cells (without DMSA-Fe2O3). However, the endocrine function for endothelin-1 and prostacyclin I-2, as well as the urea transporter function, was altered even without obvious evidence of cell injury in this context. We also showed by real-time PCR analysis that DMSA-Fe2O3 exposure resulted in differential effects on the expressions of pro- and anti-apoptosis genes of HAECs. Meanwhile, it was noted that DMSA-Fe2O3 exposure could activate the expression of genes related to oxidative stress and adhesion molecules, which suggested that inflammatory response might be evoked. Moreover, we demonstrated by in vitro endothelial tube formation that even a small amount of DMSA-Fe2O3 (0.01 and 0.02 mg/ml) could inhibit angiogenesis by the HAECs. Altogether, these results indicate that DMSA-Fe2O3 have some cytotoxicity that may cause side effects on normal endothelial cells.

  1. Effect of HSA coated iron oxide labeling on human umbilical cord derived mesenchymal stem cells

    Science.gov (United States)

    Sanganeria, Purva; Chandra, Sudeshna; Bahadur, Dhirendra; Khanna, Aparna

    2015-03-01

    Human umbilical cord derived mesenchymal stem cells (hUC-MSCs) are known for self-renewal and differentiation into cells of various lineages like bone, cartilage and fat. They have been used in biomedical applications to treat degenerative disorders. However, to exploit the therapeutic potential of stem cells, there is a requirement of sensitive non-invasive imaging techniques which will offer the ability to track transplanted cells, bio-distribution, proliferation and differentiation. In this study, we have analyzed the efficacy of human serum albumin coated iron oxide nanoparticles (HSA-IONPs) on the differentiation of hUC-MSCs. The colloidal stability of the HSA-IONPs was tested over a long period of time (≥20 months) and the optimized concentration of HSA-IONPs for labeling the stem cells was 60 μg ml-1. Detailed in vitro assays have been performed to ascertain the effect of the nanoparticles (NPs) on stem cells. Lactate dehydrogenase (LDH) assay showed minimum release of LDH depicting the least disruptions in cellular membrane. At the same time, mitochondrial impairment of the cells was also not observed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Flow cytometry analysis revealed lesser generation of reactive oxygen species in HSA-IONPs labeled hUC-MSCs in comparison to bare and commercial IONPs. Transmission electron microscopy showed endocytic engulfment of the NPs by the hUC-MSCs. During the process, the gross morphologies of the actin cytoskeleton were found to be intact as shown by immunofluorescence microscopy. Also, the engulfment of the HSA-IONPs did not show any detrimental effect on the differentiation potential of the stem cells into adipocytes, osteocytes and chondrocytes, thereby confirming that the inherent properties of stem cells were maintained.

  2. Inflammation and ER Stress Downregulate BDH2 Expression and Dysregulate Intracellular Iron in Macrophages

    Directory of Open Access Journals (Sweden)

    Susu M. Zughaier

    2014-01-01

    Full Text Available Macrophages play a very important role in host defense and in iron homeostasis by engulfing senescent red blood cells and recycling iron. Hepcidin is the master iron regulating hormone that limits dietary iron absorption from the gut and limits iron egress from macrophages. Upon infection macrophages retain iron to limit its bioavailability which limits bacterial growth. Recently, a short chain butyrate dehydrogenase type 2 (BDH2 protein was reported to contain an iron responsive element and to mediate cellular iron trafficking by catalyzing the synthesis of the mammalian siderophore that binds labile iron; therefore, BDH2 plays a crucial role in intracellular iron homeostasis. However, BDH2 expression and regulation in macrophages have not yet been described. Here we show that LPS-induced inflammation combined with ER stress led to massive BDH2 downregulation, increased the expression of ER stress markers, upregulated hepcidin expression, downregulated ferroportin expression, caused iron retention in macrophages, and dysregulated cytokine release from macrophages. We also show that ER stress combined with inflammation synergistically upregulated the expression of the iron carrier protein NGAL and the stress-inducible heme degrading enzyme heme oxygenase-1 (HO-1 leading to iron liberation. This is the first report to show that inflammation and ER stress downregulate the expression of BDH2 in human THP-1 macrophages.

  3. Intrinsic and extrinsic labeling for studies of manganese absorption in humans

    International Nuclear Information System (INIS)

    Davidsson, L.; Cederblad, A.; Hagebo, E.; Loennerdal, B.S.; Sandstroem, B.

    1988-01-01

    A dual-radioisotope method was used to simultaneously study whole-body manganese retention from a chicken liver based meal intrinsically labeled with 54 Mn and extrinsically labeled with 52 Mn. Manganese retention was monitored in a sensitive whole-body counter during approximately 30 d in six young adult women. Both radioisotopes were retained to a similar degree and excreted at identical rates. Retention at d 5 was 14.4 +/- 10.3 and 14.0 +/- 9.9% while retention at d 10 was 5.0 +/- 3.1 and 5.0 +/- 3.0% (X +/- SD) for 54 Mn and 52 Mn, respectively. From these results we conclude that the intrinsic and extrinsic Mn isotopes did form a common pool before absorption. The results can therefore be regarded as a direct validation of the use of extrinsic labeling for studies of Mn retention for estimating Mn absorption in man

  4. Tea fungus fermentation on a substrate with iron(ii-ions

    Directory of Open Access Journals (Sweden)

    Malbaša Radomir V.

    2002-01-01

    Full Text Available Iron is essential element for human metabolism and it is a constituent of both heme- containing and nonheme proteins. Its deficiency can cause serious diseases, i.e. iron-deficiency anemia, with some fatal consequences. Tea fungus beverage has high nutritional value and some pharmaceutical effects. It is widely consumed allover the world and its benefits were proved a number of times. The aim of this paper was to investigate tea fungus fermentation on a substrate containing iron(II-ions and the possibility of obtaining a beverage enriched with iron. We monitored pH, iron content and also the production of L-ascorbic acid, which is very important for iron absorption in humans.

  5. Cloud point extraction of iron(III) and vanadium(V) using 8-quinolinol derivatives and Triton X-100 and determination of 10(-7)moldm(-3) level iron(III) in riverine water reference by a graphite furnace atomic absorption spectroscopy.

    Science.gov (United States)

    Ohashi, Akira; Ito, Hiromi; Kanai, Chikako; Imura, Hisanori; Ohashi, Kousaburo

    2005-01-30

    The cloud point extraction behavior of iron(III) and vanadium(V) using 8-quinolinol derivatives (HA) such as 8-quinolinol (HQ), 2-methyl-8-quinolinol (HMQ), 5-butyloxymethyl-8-quinolinol (HO(4)Q), 5-hexyloxymethyl-8-quinolinol (HO(6)Q), and 2-methyl-5-octyloxymethyl-8-quinolinol (HMO(8)Q) and Triton X-100 solution was investigated. Iron(III) was extracted with HA and 4% (v/v) Triton X-100 in the pH range of 1.70-5.44. Above pH 4.0, more than 95% of iron(III) was extracted with HQ, HMQ, and HMO(8)Q. Vanadium(V) was also extracted with HA and 4% (v/v) Triton X-100 in the pH range of 2.07-5.00, and the extractability increased in the following order of HMQ HQ cloud point extraction was applied to the determination of iron(III) in the riverine water reference by a graphite furnace atomic absorption spectroscopy. When 1.25 x 10(-3)M HMQ and 1% (v/v) Triton X-100 were used, the found values showed a good agreement with the certified ones within the 2% of the R.S.D. Moreover, the effect of an alkyl group on the solubility of 5-alkyloxymethyl-8-quinolinol and 2-methyl-5-alkyloxymethyl-8-quinolinol in 4% (v/v) Triton X-100 at 25 degrees C was also investigated.

  6. Co-ordinated research programme on isotope-aided studies of the bioavailability of iron and zinc from human diets

    International Nuclear Information System (INIS)

    1992-01-01

    Nutritional deficiencies of essential micronutrients (particularly of iron, but also of zinc and selenium) are known to affect hundreds of millions of people throughout the world, mainly in developing countries. Such deficiencies can lead to significant deficits in mental development, growth, work performance, immune competence and other biological parameters. In many of the population groups that are affected, the deficiencies are thought to be due not to an absolute lack of the element in the diet but rather to is poor bioavailability. Much work has already been done on this subject, particularly in some developed countries and particularly with respect to iron. However, there is still appears to be a need for more research on factors affecting bioavailability and the means to improve it by simple dietary modification and fortification using food products of the kind that may be locally available in developing countries. Isotope techniques potentially have a large role to play in studies of the bioavailability of iron and other trace elements. To support work in this area, the IAEA initiated a Co-ordinated Research Programme (CRP) at the end of 1990 on ''Isotope-Aided Studies of the Bioavailability of Iron and Zinc from Human Diets''. The first Research Co-ordination Meeting (RCM) of participants in this CRP is the subject of the present report. Refs, figs and tabs

  7. Simultaneous absorption of vitamins C and E from topical microemulsions using reconstructed human epidermis as a skin model.

    Science.gov (United States)

    Rozman, Branka; Gasperlin, Mirjana; Tinois-Tessoneaud, Estelle; Pirot, Fabrice; Falson, Francoise

    2009-05-01

    Antioxidants provide the mainstay for skin protection against free radical damage. The structure of microemulsions (ME), colloidal thermodynamically stable dispersions of water, oil and surfactant, allows the incorporation of both lipophilic (vitamin E) and hydrophilic (vitamin C) antioxidants in the same system. The objective of this work was to investigate the potential of non-thickened (o/w, w/o and gel-like) and thickened (with colloidal silica) ME as carriers for the two vitamins using reconstructed human epidermis (RHE). The amounts of these vitamins accumulated in and permeated across the RHE were determined, together with factors affecting skin deposition and permeation. Notable differences were observed between formulations. The absorption of vitamins C and E in RHE layers was in general enhanced by ME compared to solutions. The incorporation of vitamins in the outer phase of ME resulted in greater absorption than that when vitamins were in the inner phase. The location of the antioxidants in the ME and affinity for the vehicle appear to be crucial in the case of non-thickened ME. Addition of thickener enhanced the deposition of vitamins E and C in the RHE. By varying the composition of ME, RHE absorption of the two vitamins can be significantly modulated.

  8. Quantitative photoacoustic integrating sphere (QPAIS platform for absorption coefficient and Grüneisen parameter measurements: Demonstration with human blood

    Directory of Open Access Journals (Sweden)

    Yolanda Villanueva-Palero

    2017-06-01

    Full Text Available Quantitative photoacoustic imaging in biomedicine relies on accurate measurements of relevant material properties of target absorbers. Here, we present a method for simultaneous measurements of the absorption coefficient and Grüneisen parameter of small volume of liquid scattering and absorbing media using a coupled-integrating sphere system which we refer to as quantitative photoacoustic integrating sphere (QPAIS platform. The derived equations do not require absolute magnitudes of optical energy and pressure values, only calibration of the setup using aqueous ink dilutions is necessary. As a demonstration, measurements with blood samples from various human donors are done at room and body temperatures using an incubator. Measured absorption coefficient values are consistent with known oxygen saturation dependence of blood absorption at 750 nm, whereas measured Grüneisen parameter values indicate variability among five different donors. An increasing Grüneisen parameter value with both hematocrit and temperature is observed. These observations are consistent with those reported in literature.

  9. Determining the refractive index of human hemoglobin solutions by Kramers-Kronig relations with an improved absorption model

    Science.gov (United States)

    Gienger, Jonas; Groß, Hermann; Neukammer, Jörg; Bär, Markus

    2016-11-01

    The real part of the refractive index (RI) of aqueous solutions of human hemoglobin is computed from their absorption spectra in the wavelength range $250\\,{\\rm nm} - 1100\\,{\\rm nm}$ using the Kramers-Kronig (KK) relations and the corresponding uncertainty analysis is provided. The strong ultraviolet (UV) and infrared absorbance of the water outside this spectral range were taken into account in a previous study employing KK relations. We improve these results by including the concentration dependence of the water absorbance as well as by modeling the deep UV absorbance of hemoglobin's peptide backbone. The two free parameters of the model for the deep UV absorbance are fixed by a global fit.

  10. Involvement of the Cys-Tyr cofactor on iron binding in the active site of human cysteine dioxygenase.

    Science.gov (United States)

    Arjune, Sita; Schwarz, Guenter; Belaidi, Abdel A

    2015-01-01

    Sulfur metabolism has gained increasing medical interest over the last years. In particular, cysteine dioxygenase (CDO) has been recognized as a potential marker in oncology due to its altered gene expression in various cancer types. Human CDO is a non-heme iron-dependent enzyme, which catalyzes the irreversible oxidation of cysteine to cysteine sulfinic acid, which is further metabolized to taurine or pyruvate and sulfate. Several studies have reported a unique post-translational modification of human CDO consisting of a cross-link between cysteine 93 and tyrosine 157 (Cys-Tyr), which increases catalytic efficiency in a substrate-dependent manner. However, the reaction mechanism by which the Cys-Tyr cofactor increases catalytic efficiency remains unclear. In this study, steady-state kinetics were determined for wild type CDO and two different variants being either impaired or saturated with the Cys-Tyr cofactor. Cofactor formation in CDO resulted in an approximately fivefold increase in k cat and tenfold increase in k cat/K m over the cofactor-free CDO variant. Furthermore, iron titration experiments revealed an 18-fold decrease in K d of iron upon cross-link formation. This finding suggests a structural role of the Cys-Tyr cofactor in coordinating the ferrous iron in the active site of CDO in accordance with the previously postulated reaction mechanism of human CDO. Finally, we identified product-based inhibition and α-ketoglutarate and glutarate as CDO inhibitors using a simplified well plate-based activity assay. This assay can be used for high-throughput identification of additional inhibitors, which may contribute to understand the functional importance of CDO in sulfur amino acid metabolism and related diseases.

  11. Effect of room absorption on human vocal output in multitalker situations.

    Science.gov (United States)

    Nijs, Lau; Saher, Konca; den Ouden, Daniël

    2008-02-01

    People increase their vocal output in noisy environments. This is known as the Lombard effect. The aim of the present study was to measure the effect as a function of the absorption coefficient. The noise source was generated by using other talkers in the room. A-weighted sound levels were measured in a 108 m(3) test room. The number of talkers varied from one to four and the absorption coefficients from 0.12 to 0.64. A model was introduced based on the logarithmic sum of the level found in an anechoic room plus the increasing portion of noise levels up to 80 dB. Results show that the model fits the measurements when a maximum slope of 0.5 dB per 1.0 dB increase in background level is used. Hence Lombard slopes vary from 0.2 dBdB at 50 dB background level to 0.5 dBdB at 80 dB. In addition, both measurements and the model predict a decrease of 5.5 dB per doubling of absorbing area in a room when the number of talkers is constant. Sound pressure levels increase for a doubling of talkers from 3 dB for low densities to 6 dB for dense crowds. Finally, there was correspondence between the model estimation and previous measurements reported in the literature.

  12. Computational Studies of Drug Release, Transport and Absorption in the Human Intestines

    Science.gov (United States)

    Behafarid, Farhad; Brasseur, J. G.; Vijayakumar, G.; Jayaraman, B.; Wang, Y.

    2016-11-01

    Following disintegration of a drug tablet, a cloud of particles 10-200 μm in diameter enters the small intestine where drug molecules are absorbed into the blood. Drug release rate depends on particle size, solubility and hydrodynamic enhancements driven by gut motility. To quantify the interrelationships among dissolution, transport and wall permeability, we apply lattice Boltzmann method to simulate the drug concentration field in the 3D gut released from polydisperse distributions of drug particles in the "fasting" vs. "fed" motility states. Generalized boundary conditions allow for both solubility and gut wall permeability to be systematically varied. We apply a local 'quasi-steady state' approximation for drug dissolution using a mathematical model generalized for hydrodynamic enhancements and heterogeneity in drug release rate. We observe fundamental differences resulting from the interplay among release, transport and absorption in relationship to particle size distribution, luminal volume, motility, solubility and permeability. For example, whereas smaller volume encourages higher bulk concentrations and reduced release rate, it also encourages higher absorption rate, making it difficult to generalize predictions. Supported by FDA.

  13. Human Vitamin B12 Absorption and Metabolism are Measured by Accelerator Mass Spectrometry Using Specifically Labeled 14C-Cobalamin

    International Nuclear Information System (INIS)

    Carkeet, C; Dueker, S R; Lango, J; Buchholz, B A; Miller, J W; Green, R; Hammock, B D; Roth, J R; Anderson, P J

    2006-01-01

    There is need for an improved test of human ability to assimilate dietary vitamin B 12 . Assaying and understanding absorption and uptake of B 12 is important because defects can lead to hematological and neurological complications. Accelerator mass spectrometry (AMS) is uniquely suited for assessing absorption and kinetics of 14 C-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of carbon-14 ( 14 C) in microliter volumes of biological samples, with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B 12 in the range of normal dietary intake. The B 12 used was quantitatively labeled with 14 C at one particular atom of the DMB moiety by exploiting idiosyncrasies of Salmonellametabolism. In order to grow aerobically on ethanolamine, S. entericamust be provided with either pre-formed B 12 or two of its precursors: cobinamide and dimethylbenzimidazole (DMB). When provided with 14 C-DMB specifically labeled in the C2 position, cells produced 14 C-B 12 of high specific activity (2.1 GBq/mmol, 58 mCi/mmol) and no detectable dilution of label from endogenous DMB synthesis. In a human kinetic study, a physiological dose (1.5 mg, 2.2 KBq/59 nCi) of purified 14 C-B 12 was administered and showed plasma appearance and clearance curves consistent with the predicted behavior of the pure vitamin. This method opens new avenues for study of B 12 assimilation

  14. Simulation study of the thermal and the thermoelastic effects induced by pulsed laser absorption in human skin

    Science.gov (United States)

    Kim, Jae-Young; Jang, Kyungmin; Yang, Seung-Jin; Baek, Jun-Hyeok; Park, Jong-Rak; Yeom, Dong-Il; Kim, Ji-Sun; Kim, Hyung-Sik; Jun, Jae-Hoon; Chung, Soon-Cheol

    2016-04-01

    We studied the thermal and the mechanical effects induced by pulsed laser absorption in human skin by numerically solving the heat-transfer and the thermoelastic wave equations. The simulation of the heat-transfer equation yielded the spatiotemporal distribution of the temperature increase in the skin, which was then used in the driving term of the thermoelastic wave equation. We compared our simulation results for the temperature increase and the skin displacements with the measured and numerical results, respectively. For the comparison, we used a recent report by Jun et al. [Sci. Rep. 5, 11016 (2015)], who measured in vivo skin temperature and performed numerical simulation of the thermoelastic wave equation using a simple assumption about the temporal evolution of the temperature distribution, and found their results to be in good agreement with our results. In addition, we obtained solutions for the stresses in the human skin and analyzed their dynamic behaviors in detail.

  15. Lipid accumulation in human breast cancer cells injured by iron depletors.

    Science.gov (United States)

    De Bortoli, Maida; Taverna, Elena; Maffioli, Elisa; Casalini, Patrizia; Crisafi, Francesco; Kumar, Vikas; Caccia, Claudio; Polli, Dario; Tedeschi, Gabriella; Bongarzone, Italia

    2018-04-03

    Current insights into the effects of iron deficiency in tumour cells are not commensurate with the importance of iron in cell metabolism. Studies have predominantly focused on the effects of oxygen or glucose scarcity in tumour cells, while attributing insufficient emphasis to the inadequate supply of iron in hypoxic regions. Cellular responses to iron deficiency and hypoxia are interlinked and may strongly affect tumour metabolism. We examined the morphological, proteomic, and metabolic effects induced by two iron chelators-deferoxamine (DFO) and di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT)-on MDA-MB-231 and MDA-MB-157 breast cancer cells. These chelators induced a cytoplasmic massive vacuolation and accumulation of lipid droplets (LDs), eventually followed by implosive, non-autophagic, and non-apoptotic death similar to methuosis. Vacuoles and LDs are generated by expansion of the endoplasmic reticulum (ER) based on extracellular fluid import, which includes unsaturated fatty acids that accumulate in LDs. Typical physiological phenomena associated with hypoxia are observed, such as inhibition of translation, mitochondrial dysfunction, and metabolic remodelling. These survival-oriented changes are associated with a greater expression of epithelial/mesenchymal transcription markers. Iron starvation induces a hypoxia-like program able to scavenge nutrients from the extracellular environment, and cells assume a hypertrophic phenotype. Such survival strategy is accompanied by the ER-dependent massive cytoplasmic vacuolization, mitochondrial dysfunctions, and LD accumulation and then evolves into cell death. LDs containing a greater proportion of unsaturated lipids are released as a consequence of cell death. The consequence of the disruption of iron metabolism in tumour tissue and the effects of LDs on intercellular communication, cancer-inflammation axis, and immunity remain to be explored. Considering the potential benefits, these are crucial

  16. Incorporation of Trace Elements in Ancient and Modern Human Bone: An X-Ray Absorption Spectroscopy Study

    Science.gov (United States)

    Pingitore, N. E.; Cruz-Jimenez, G.; Price, T. D.

    2001-12-01

    X-ray absorption spectroscopy (XAS) affords the opportunity to probe the atomic environment of trace elements in human bone. We are using XAS to investigate the mode(s) of incorporation of Sr, Zn, Pb, and Ba in both modern and ancient (and thus possibly altered) human and animal bone. Because burial and diagenesis may add trace elements to bone, we performed XAS analysis on samples of pristine contemporary and ancient, buried human and animal bone. We assume that deposition of these elements during burial occurs by processes distinct from those in vivo, and this will be reflected in their atomic environments. Archaeologists measure strontium in human and animal bone as a guide to diet. Carnivores show lower Sr/Ca ratios than their herbivore prey due to discrimination against Sr relative to Ca up the food chain. In an initial sample suite no difference was observed between modern and buried bone. Analysis of additional buried samples, using a more sensitive detector, revealed significant differences in the distance to the second and third neighbors of the Sr in some of the buried samples. Distances to the first neighbor, oxygen, were similar in all samples. Zinc is also used in paleo-diet studies. Initial x-ray absorption spectroscopy of a limited suite of bones did not reveal any differences between modern and buried samples. This may reflect the limited number of samples examined or the low levels of Zn in typical aqueous solutions in soils. Signals from barium and lead were too low to record useful XAS spectra. Additional samples will be studied for Zn, Ba, and Pb. We conducted our XAS experiments on beam lines 4-1 and 4-3 at the Stanford Synchrotron Radiation Laboratory. Data were collected in the fluorescence mode, using a Lytle detector and appropriate filter, and a solid state, 13-element Ge-detector.

  17. Mechanisms of complement activation by dextran-coated superparamagnetic iron oxide (SPIO) nanoworms in mouse versus human serum

    DEFF Research Database (Denmark)

    Banda, Nirmal K; Mehta, Gaurav; Chao, Ying

    2014-01-01

    BACKGROUND: The complement system is a key component of innate immunity implicated in the neutralization and clearance of invading pathogens. Dextran coated superparamagnetic iron oxide (SPIO) nanoparticle is a promising magnetic resonance imaging (MRI) contrast agent. However, dextran SPIO has...... the mechanisms of human complement activation. Mouse data were analyzed by non-paired t-test, human data were analyzed by ANOVA followed by multiple comparisons with Student-Newman-Keuls test. RESULTS: In mouse sera, SPIO NW triggered the complement activation via the LP, whereas the AP contributes via...... the CP, but that did not affect the total level of C3 deposition on the particles. CONCLUSIONS: There were important differences and similarities in the complement activation by SPIO NW in mouse versus human sera. Understanding the mechanisms of immune recognition of nanoparticles in mouse and human...

  18. Iron Modifies Plasma FGF23 Differently in Autosomal Dominant Hypophosphatemic Rickets and Healthy Humans

    Science.gov (United States)

    Peacock, Munro; Gray, Amie K.; Padgett, Leah R.; Hui, Siu L.; Econs, Michael J.

    2011-01-01

    Context: In autosomal dominant hypophosphatemic rickets (ADHR), fibroblast growth factor 23 (FGF23) resists cleavage, causing increased plasma FGF23 levels. The clinical phenotype includes variable onset during childhood or adulthood and waxing/waning of hypophosphatemia. Delayed onset after puberty in females suggests iron status may be important. Objective: Studies were performed to test the hypothesis that plasma C-terminal and intact FGF23 concentrations are related to serum iron concentrations in ADHR. Design and Setting: Cross-sectional and longitudinal studies of ADHR and a cross-sectional study in healthy subjects were conducted at an academic medical center. Participants: Participants included 37 subjects with ADHR mutations from four kindreds and 158 healthy adult controls. Main Outcome Measure: The relationships of serum iron concentrations with plasma C-terminal and intact FGF23 concentrations were evaluated. Results: Serum phosphate and 1,25-dihydroxyvitamin D correlated negatively with C-terminal FGF23 and intact FGF23 in ADHR but not in controls. Serum iron was negatively correlated to both C-terminal FGF23 (r = −0.386; P < 0.05) and intact FGF23 (r = −0.602; P < 0.0001) in ADHR. However, control subjects also demonstrated a negative relationship of serum iron with C-terminal FGF23 (r = −0.276; P < 0.001) but no relationship with intact FGF23. Longitudinally in ADHR subjects, C-terminal FGF23 and intact FGF23 concentrations changed negatively with iron concentrations (P < 0.001 and P = 0.055, respectively), serum phosphate changed negatively with C-terminal FGF23 and intact FGF23 (P < 0.001), and there was a positive relationship between serum iron and phosphate (P < 0.001). Conclusions: Low serum iron is associated with elevated FGF23 in ADHR. However, in controls, low serum iron was also associated with elevated C-terminal FGF23, but not intact FGF23, suggesting cleavage maintains homeostasis despite increased FGF23 expression. PMID:21880793

  19. Determination of cobalt in human biological liquids from electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dragan, Felicia [University of Oradea, Faculty of Medicine and Pharmacy, 29 N Jiga, 410028 Oradea (Romania); HIncu, Lucian [University of Medicine and Pharmacy ' Carol Davila' , Faculty of Pharmacy, 6 Traian Vuia, 020956 Bucuresti (Romania); Bratu, Ioan, E-mail: fdragan@uoradea.r [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)

    2009-08-01

    Problems and possibilities of the determination of Co in serum and urine samples by electrothermal atomic absorption spectrometry (ETAAS) are described. Optimal instrumental parameters as well as a suitable atomizer, calibration procedure and hydrogen peroxide as modifier are proposed for direct ETAAS measurement of Co in serum and urine. The detection limit achieved was 0.1 {mu}g L{sup -1} for both matrices and relative standard deviations varied in the range 5-20% depending on the Co concentration in the sample. The validity of the method was verified by the analyses of standard reference materials. For serum samples with Co content lower than the detection limit, a separation and preconcentration procedure based on liquid/liquid extraction is suggested prior to determination of Co in the organic phase by ETAAS. This procedure permits determination of 0.02 {mu}g L{sup -1} Co in serum samples with a relative standard deviation of 10-18%.

  20. Ingestion of polydextrose increase the iron absorption in rats submitted to partial gastrectomy A ingestão de polidextrose aumenta a absorção de ferro em ratos submetidos à gastrectomia parcial

    Directory of Open Access Journals (Sweden)

    Elisvânia Freitas dos Santos

    2010-12-01

    Full Text Available PURPOSE: To investigate whether polydextrose stimulates iron absorption in rats submitted to partial gastrectomy and sham operated. METHODS: The rats were submitted to partial gastrectomy (Billroth II or laparotomy (sham-operated control, in groups of 20 and 20 each respectively. The animals were fed with a control diet (AIN-93M without polydextrose or a diet containing polydextrose (50g/Kg of diet for eight weeks. They were divided into four subgroups: sham-operated and Billroth II gastrectomy and with or without polydextrose. Two animals died during the experiment. All rats submitted to gastrectomy received B-12 vitamin (intramuscular each two weeks. The hematocrit and hemoglobin concentration were measured at the start and on day 30 and 56 after the beginning of the experimental period. At the end of the study, the blood was collected for determination of serum iron concentration. RESULTS: The diet with polydextrose reduced the excretion of iron. Apparent iron absorption was higher in the polydextrose fed groups than in the control group. The haematocrit and haemoglobin concentration were lower after Billroth II gastrectomy rats fed the control diet as compared to the polydextrose diet groups. CONCLUSION: Polydextrose increase iron absorption and prevents postgastrectomy anemia.OBJETIVO: Investigar se a polidextrose estimula a absorção de ferro em ratos submetidos à gastrectomia parcial e sham operados. MÉTODOS: Os ratos foram submetidos à gastrectomia parcial (Billroth II e à laparotomia (controle sham-operados em grupos de 20 e 20 cada, respectivamente. Os animais foram alimentados com uma dieta controle (AIN-93M, sem polidextrose ou uma dieta contendo polidextrose (50g/kg de dieta durante oito semanas. Foram divididos em quatro grupos: sham-operados e com gastrectomia BII e com ou sem polidextrose. Dois animais morreram durante o experimento. Todos os ratos com gastrectomia receberam vitamina B-12 (intramuscular a cada duas semanas

  1. Flame atomic absorption spectrometric determination of zinc, nickel, iron and lead in different matrixes after solid phase extraction on sodium dodecyl sulfate (SDS)-coated alumina as their bis (2-hydroxyacetophenone)-1, 3-propanediimine chelates

    International Nuclear Information System (INIS)

    Ghaedi, M.; Tavallali, H.; Shokrollahi, A.; Zahedi, M.; Montazerozohori, M.; Soylak, M.

    2009-01-01

    A sensitive and simple solid phase extraction method for the simultaneous determination of trace and toxic metals in food samples has been reported. The method is based on the adsorption of zinc, nickel, iron and lead on sodium dodecyl sulfate (SDS)-coated alumina, which is also chelated with bis (2-hydroxyacetophenone)-1, 3-propanediimine (BHAPN). The retained analyte ions on modified solid phase were eluted using 8 mL of 4 mol L -1 HNO 3 . The analyte determinations were carried out by flame atomic absorption spectrometry. The influences of some metal ions and anions on the recoveries of understudy analyte ions were investigated. The proposed method has been successfully applied for the evaluation of these trace and toxic metals in some traditional food samples from Iran.

  2. The effect of human resource practices on psychological contracts at an iron ore mining company in South Africa

    Directory of Open Access Journals (Sweden)

    Caren B. Scheepers

    2011-08-01

    Full Text Available Orientation: Human resource practices influence the psychological contract between employee and employer and, ultimately, organisational performance. Research purpose: The objective of this study was to examine the effect of human resource practices on the types of psychological contracts in an iron ore mining company in South Africa empirically. Motivation for the study: Although there have been a number of conceptual studies on the effect of human resource practices on psychological contracts, there has been no effort to synthesise the links between these contracts and various human resource practices systematically. This study endeavoured to provide quantitative evidence to verify or refute conceptual studies on this relationship. Its findings could inform human resource strategies and, ultimately, the prioritisation of human resource practices to improve the cost-effective allocation of resources. Research design, approach and method: The researchers administered two questionnaires. These were Rousseau’s Psychological Contract Inventory (2000 and the Human Resource Practices Scale of Geringer, Colette and Milliman (2002. The researchers conducted the study with 936 knowledge workers at an iron ore mining company in South Africa. They achieved a 32% response rate. Main findings: The findings showed that most participants have relational contracts with the organisation. Another 22% have balanced contracts, 8% have transitional contracts whilst only 1% have transactional contracts. The study suggests that there are relationships between these psychological contracts and specific human resource practices. The study found that training and development was the most important human resource practice for developing relational and balanced contracts. Employees thought that they contributed more than their employer did to the relationship. The researchers developed a model to illustrate the influence of the various human resource practices on

  3. Muscle tension increases impact force but decreases energy absorption and pain during visco-elastic impacts to human thighs.

    Science.gov (United States)

    Tsui, Felix; Pain, Matthew T G

    2018-01-23

    Despite uncertainty of its exact role, muscle tension has shown an ability to alter human biomechanical response and may have the ability to reduce impact injury severity. The aim of this study was to examine the effects of muscle tension on human impact response in terms of force and energy absorbed and the subjects' perceptions of pain. Seven male martial artists had a 3.9 kg medicine ball dropped vertically from seven different heights, 1.0-1.6 m in equal increments, onto their right thigh. Subjects were instructed to either relax or tense the quadriceps via knee extension (≥60% MVC) prior to each impact. F-scan pressure insoles sampling at 500 Hz recorded impact force and video was recorded at 1000 Hz to determine energy loss from the medicine ball during impact. Across all impacts force was 11% higher, energy absorption was 15% lower and time to peak force was 11% lower whilst perceived impact intensity was significantly lower when tensed. Whether muscle is tensed or not had a significant and meaningful effect on perceived discomfort. However, it did not relate to impact force between conditions and so tensing may alter localised injury risk during human on human type impacts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Cloud point extraction of copper, lead, cadmium, and iron using 2,6-diamino-4-phenyl-1,3,5-triazine and nonionic surfactant, and their flame atomic absorption spectrometric determination in water and canned food samples.

    Science.gov (United States)

    Citak, Demirhan; Tuzen, Mustafa

    2012-01-01

    A cloud point extraction procedure was optimized for the separation and preconcentration of lead(II), cadmium(II), copper(II), and iron(III) ions in various water and canned food samples. The metal ions formed complexes with 2,6-diamino-4-phenyl-1,3,5-triazine that were extracted by surfactant-rich phases in the nonionic surfactant Triton X-114. The surfactant-rich phase was diluted with 1 M HNO3 in methanol prior to its analysis by flame atomic absorption spectrometry. The parameters affecting the extraction efficiency of the proposed method, such as sample pH, complexing agent concentration, surfactant concentration, temperature, and incubation time, were optimized. LOD values based on three times the SD of the blank (3Sb) were 0.38, 0.48, 1.33, and 1.85 microg/L for cadmium(II), copper(II), lead(II), and iron(III) ions, respectively. The precision (RSD) of the method was in the 1.86-3.06% range (n=7). Validation of the procedure was carried out by analysis of National Institute of Standards and Technology Standard Reference Material (NIST-SRM) 1568a Rice Flour and GBW 07605 Tea. The method was applied to water and canned food samples for determination of metal ions.

  5. Comparison of the gastrointestinal absorption and bioavailability of fenofibrate and fenofibric acid in humans.

    Science.gov (United States)

    Zhu, Tong; Ansquer, Jean-Claude; Kelly, Maureen T; Sleep, Darryl J; Pradhan, Rajendra S

    2010-08-01

    This study compared the gastrointestinal (GI) absorption characteristics and absolute bioavailability of fenofibric acid and fenofibrate (which is converted to fenofibric acid in vivo) in healthy volunteers. Treatments were delivered to the proximal small bowel, distal small bowel, and colon using a site-specific delivery system (Enterion capsule) and to the stomach by oral administration of equimolar doses. Serial blood samples were collected for 120 hours postdose and assayed for plasma fenofibric acid concentrations. The absolute bioavailability of each treatment was determined relative to 50 mg of fenofibric acid administered intravenously. Plasma exposure to fenofibric acid following fenofibric acid administration was approximately 1.5 times higher than that following fenofibrate administration for delivery to the proximal and distal small bowel and following oral administration, and it was approximately 5 times higher following colon delivery. The absolute bioavailability in the stomach, proximal small bowel, distal small bowel, and colon was approximately 81%, 88%, 84%, and 78%, respectively, for fenofibric acid and 69%, 73%, 66%, and 22%, respectively, for fenofibrate (P < .0001 and P = .033 for fenofibric acid vs fenofibrate in the colon and distal small bowel, respectively). In conclusion, fenofibric acid is well absorbed throughout the GI tract and has greater bioavailability than fenofibrate in all GI regions.

  6. Dermal absorption of benzo[a]pyrene into human skin from soil: Effect of artificial weathering, concentration, and exposure duration.

    Science.gov (United States)

    Peckham, Trevor K; Shirai, Jeffry H; Bunge, Annette L; Lowney, Yvette W; Ruby, Michael V; Kissel, John C

    2017-11-01

    In vitro assessments of 14 C-benzo[a]pyrene (BaP) absorption through human epidermis were conducted with the sub-63-μm fraction of four test soils containing different amounts of organic and black carbon. Soils were artificially weathered for eight weeks and applied to epidermis at nominal BaP concentrations of 3 and 10 mg/kg for 8 or 24 h. Experiments were also conducted at 24 h with unweathered soils and with BaP deposited onto skin from acetone at a comparable chemical load. For the weathered soils, absorption was independent of the amount of organic or black carbon, the mass in the receptor fluid was proportional to exposure duration but independent of concentration, and the mass recovered in the skin after washing was proportional to concentration and independent of exposure time. Results from the weathered and unweathered soils were similar except for the mass recovered in the washed skin, which was lower for the weathered soil only at the higher concentration. We hypothesize that chemical concentrations exceeded the BaP sorption capacity accessible within the artificial weathering timeframe for all soils tested, and that BaP mass in the washed skin was dominated by particles that were not removed by washing. Fluxes into and through skin from soils were lower by an order of magnitude than from acetone-deposited BaP.

  7. Iron deprivation induces apoptosis independently of p53 in human and murine tumour cells

    Czech Academy of Sciences Publication Activity Database

    Truksa, Jaroslav; Kovář, Jan; Valenta, Tomáš; Ehrlichová, Marie; Polák, J.; Naumann, P. W.

    2003-01-01

    Roč. 36, č. 4 (2003), s. 199-213 ISSN 0960-7722 R&D Projects: GA ČR GA301/01/0041 Keywords : iron deprivation * p53 * apoptosis induction Subject RIV: EB - Gene tics ; Molecular Biology Impact factor: 1.529, year: 2003

  8. Monte Carlo simulation for the estimation of iron in human whole ...

    Indian Academy of Sciences (India)

    The simulation shows that theobtained results are in good agreement with experimental data, and better than the theoretical XCOM values. The study indicates that MCNP simulation is an excellent tool to estimate the iron concentration in the blood samples. The MCNP code can also be utilized to estimate other trace ...

  9. Radioisotopes of iron in investigation of anaemia in malnutrition

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, K [Institute of Nuclear Medicine, Dacca (Bangladesh)

    1979-06-01

    Iron absorption from a simple breakfast meal by a normal adult was done by the whole body counting system and blood radioactivity measurement. Results seem to be in good agreement and both the methods are found to be standard for measurements of iron absorption from food. In iron deficiency anaemia associated with malnutrition improvement of nutritional condition has been found to increase both haemoglobin level and iron absorption possibly by way of improving the ability of intestinal mucosa to absorb more iron from food and by better utilization of iron by erythropoietic system. Thus improvement of nutritional status is a prerequisite to treatment of iron deficiency anaemia.

  10. Radioisotopes of iron in investigation of anaemia in malnutrition

    International Nuclear Information System (INIS)

    Ahmed, K.

    1979-01-01

    Iron absorption from a simple breakfast meal by a normal adult was done by the whole body counting system and blood radioactivity measurement. Results seem to be in good agreement and both the methods are found to be standard for measurements of iron absorption from food. In iron deficiency anaemia associated with malnutrition improvement of nutritional condition has been found to increase both haemoglobin level and iron absorption possibly by way of improving the ability of intestinal mucosa to absorb more iron from food and by better utilization of iron by erythropoietic system. Thus improvement of nutritional status is a prerequisite to treatment of iron deficiency anaemia. (author)

  11. Estado nutricional e absorção intestinal de ferro em crianças com doença hepática crônica com e sem colestase Nutritional status and intestinal iron absorption in children with chronic hepatic disease with and without cholestasis

    Directory of Open Access Journals (Sweden)

    Regina Helena Guedes da Motta Mattar

    2005-08-01

    Full Text Available OBJETIVO: Avaliar a ingestão alimentar, a ocorrência de desnutrição energético-protéica e de anemia e a absorção intestinal de ferro em crianças com doença hepática crônica. CASUÍSTICA E MÉTODOS: Foram estudados 25 pacientes com doença hepática crônica, sendo 15 com colestase e 11 sem colestase. A idade variou entre 6,5 meses e 12,1 anos. A absorção intestinal de ferro foi avaliada pela elevação do ferro sérico uma hora após a ingestão de 1 mg/kg de ferro elementar e pela resposta à ferroterapia oral. A absorção intestinal de ferro foi comparada com um grupo de crianças com anemia ferropriva. RESULTADOS: A ingestão média de energia e proteínas nos pacientes com doença hepática com colestase foi maior do que nos pacientes sem colestase. O déficit nutricional foi mais grave nos pacientes com colestase, predominando os déficits de estatura-idade e peso-idade. A anemia foi freqüente tanto nas crianças com doença hepática com colestase (11/14; 78,6% como nas sem colestase (7/11; 63,6%. Na doença hepática com colestase, observou-se menor (p OBJECTIVES: to evaluate food intake, occurrence of energy-protein malnutrition and anemia, and intestinal iron absorption in children with chronic liver disease. METHODS: The study included 25 children with chronic liver disease, 15 with cholestasis and 11 without cholestasis. The age varied between 6.5 months and 12.1 years. Intestinal iron absorption was evaluated by the increment of serum iron one hour after the ingestion of 1 mg/kg of elemental iron and by the response to oral iron therapy. Iron intestinal absorption was compared to a group with iron deficiency anemia (without liver disease. RESULTS: The mean intake of energy and protein in the cholestatic group was higher than in patients without cholestasis. The nutritional deficit was more severe in cholestatic patients, especially with regard to height-for-age and weight-for-age indices. Anemia was found in both

  12. Serum iron and total iron binding capacity levels among the abo ...

    African Journals Online (AJOL)

    Iron deficiency anaemia is a common tropical disease. Iron plays a very important role in the human body. The understanding of the different blood groups ability to retain iron in their system can give an insight into their ability to handle the disease Iron deficiency anaemia. Serum Iron, Total Iron Binding Capacity (TIBC) and ...

  13. An analysis of lead (Pb) from human hair samples (20-40 years of age) by atomic absorption spectrophotometry

    Energy Technology Data Exchange (ETDEWEB)

    Gelsano, Flordeliza K; Timing, Laurie D

    2003-02-17

    This analysis of lead from human hair samples in five different groups namely scavengers from Payatas Quezon City, tricycle drivers, car shop workers, paint factory workers, and students from Polytechnic University of the Philippines. The people from Nagcarlan, Laguna represented as a ''base-line value'' or as a control group. The method applied was acid digestion using HNO{sub 3} and HClO{sub 4} then the samples were subjected to atomic absorption spectrophotometer. In terms of lead found from hair, the scavengers from Payatas Q.C. obtained high exposure of lead among the samples that were tested. The result of the analysis of concentration of lead was expressed in mg/L. (Authors)

  14. An analysis of lead (Pb) from human hair samples (20-40 years of age) by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Gelsano, Flordeliza K.; Timing, Laurie D.

    2003-01-01

    This analysis of lead from human hair samples in five different groups namely scavengers from Payatas Quezon City, tricycle drivers, car shop workers, paint factory workers, and students from Polytechnic University of the Philippines. The people from Nagcarlan, Laguna represented as a ''base-line value'' or as a control group. The method applied was acid digestion using HNO 3 and HClO 4 then the samples were subjected to atomic absorption spectrophotometer. In terms of lead found from hair, the scavengers from Payatas Q.C. obtained high exposure of lead among the samples that were tested. The result of the analysis of concentration of lead was expressed in mg/L. (Authors)

  15. Isotope-aided studies of the bioavailability of iron from diets and fortified foods to be used in iron fortifications programmes in Chile and Ecuador: Validation of in vitro techniques

    International Nuclear Information System (INIS)

    Hertrampf, E.; Pizarro, F.; Olivares, M.; Walter, T.; Fuenmayor, G.; Estevez, E.; Yepez, R.

    1992-01-01

    In selected typical Ecuatorian foods to be used in nutritional intervention programmes, we measured iron bioavailability in humans, with a double isotopic method. The interaction with some accompanied foods or beverages was also studied. Iron bioavailability from wheat flour foods was good (9%). When vermicelli soup was eaten together with lemonade sweetened with raw sugar cane, mean iron absorption was the highest (15%). Camomile infusion do not affect iron absorption from bread. At the same time, we will validate an in vitro iron availability technique comparing it with the results obtained in other laboratories involved in the present CRP and with the results obtained in the same foods with in vivo double isotopic. We will also start studies of in vitro zinc availability. (author). 26 refs, 2 figs, 7 tabs

  16. The effects of metamaterial on electromagnetic fields absorption characteristics of human eye tissues.

    Science.gov (United States)

    Gasmelseed, Akram; Yunus, Jasmy

    2014-01-01

    The interaction of a dipole antenna with a human eye model in the presence of a metamaterial is investigated in this paper. The finite difference time domain (FDTD) method with convolutional perfectly matched layer (CPML) formulation have been used. A three-dimensional anatomical model of the human eye with resolution of 1.25 mm × 1.25 mm × 1.25 mm was used in this study. The dipole antenna was driven by modulated Gaussian pulse and the numerical study is performed with dipole operating at 900 MHz. The analysis has been done by varying the size and value of electric permittivity of the metamaterial. By normalizing the peak SAR (1 g and 10 g) to 1 W for all examined cases, we observed how the SAR values are not affected by the different permittivity values with the size of the metamaterial kept fixed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. In-vitro percutaneous absorption of losartan potassium in human skin and prediction of human skin permeability

    Directory of Open Access Journals (Sweden)

    Petkar K.C.

    2007-05-01

    Full Text Available This study describes the feasibility of transdermal controlled administration of Losartan potassium (LP across human cadaver skin. Study also defines the influence of capsaicin, sex and site of application on permeation characteristics and determined an appropriate animal model for human skin permeability. The permeation of LP of various formulations was studied using Keshary-Chein diffusion cell. Optimized controlled formulation (without capsaicin released 42.17% (±1.85 of LP in 12 hr whereas treatment formulation (with capsaicin 0.028 % w/v released 48.94% (±1.71 of LP with significant difference on null hypothesis. Influence of sex showed statistically significant difference for permeation of LP through male and female rats, as well as male and female mice across both the abdominal and dorsal sides of the skin (p<0.05. Similarly statistically significant differences were noted for permeation of LP across male and female mice abdomen-dorsal, but not for male rat abdomen-dorsal and female rat abdomen-dorsal. Furthermore, in-vitro permeation of LP across human skin was compared with the permeation across rat and mice skins. Male rat and male mice dorsal skin was found to have closer permeability characteristics to human than other skin membranes, but the Factor of Difference values were < 3 for all membranes which were used suggesting the membranes are good models for human skin permeability. In conclusion simple transdermal adhesive patches formulations incorporating high molecular weight of LP can deliver a dose in-vivo and proposed model skin membranes can be utilized for future pharmacokineic and toxicokinetic studies as well as metabolism studies of LP

  18. Evaluation of cadmium, lead, copper, iron and zinc in Turkish dietary vegetable oils and olives using electrothermal and flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Acar, O.

    2012-07-01

    The Cd, Pb, Cu, Fe and Zn contents of some edible vegetable oils (soybean, sunflower, flower, nut, corn and olive) and of olives (olive-1, black, green, black crushed with seeds and green crushed with seeds) were determined and evaluated by an electrothermal atomic absorption spectrometer (ETAAS) using an Sc + Ir + NH{sub 4}H{sub 2}PO{sub 4} chemical modifier mixture and flame atomic absorption spectrometer (FAAS) after microwave digestion. The pyrolysis and atomization temperatures of Cd, Pb and Cu in sample solutions with and without the modifier mixture were investigated. The limits of detection (LOD) for analytes found are 0.1, 0.6, 0.9, 15.0 and 12.0 {mu}g L{sup -}1 for Cd, Cu, Pb, Fe and Zn, respectively. The accuracy of the procedure proposed was confirmed by analyzing bovine liver 1577b standard reference material (SRM) and a spiked sample solution. The results of the analytes found were compared with certified and added values. The relative standard deviations of the analytes found were lower than 7% and the percent of recoveries obtained ranges from 96 to 101%. The Sc + Ir + NH{sub 4}H{sub 2}PO{sub 4} mixture proposed was applied for the determination of Cd, Pb and Cu in oils and olives. The results of analytes found in the samples were compared with international and national food quality guidelines as well as with literature values. (Author) 48 refs.

  19. Monitoring content of cadmium, calcium, copper, iron, lead, magnesium and manganese in tea leaves by electrothermal and flame atomizer atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Prkić Ante

    2017-08-01

    Full Text Available Due to the simplicity of tea preparation (pouring hot water onto different dried herbs and its high popularity as a beverage, monitoring and developing a screening methodology for detecting the metal content is very important. The concentrations of Cd, Ca, Cu, Fe, Pb, Mg and Mn in 11 different samples of sage (Salvia officinalis L., linden (Tilia L. and chamomile (Matricaria chamomilla L. purchased at local herbal pharmacy were determined using electrothermal atomizer atomic absorption spectrometry (ETAAS and flame atomizer atomic absorption spectrometry (FAAS. The concentrations determined were: Cd (0.012 – 0.470 mg kg−1, Ca (5209 – 16340 mg kg−1, Cu (22.01 – 33.05 mg kg−1, Fe (114.2 – 440.3 mg kg−1, Pb (0.545 – 2.538 mg kg−1, Mg (2649 – 4325 mg kg−1 and Mn (34.00 – 189.6 mg kg−1. Principal Component Analysis (PCA was applied to identify factors (soil and climate influencing the content of the measured elements in herbal samples. The proposed methodology developed in this work was successfully applied to the detection of metals in herbal samples. The analysis showed that the content of toxic metals in herbal teas was below the maximum dose recommended by the World Health Organization (WHO.

  20. Evaluation of cadmium, lead, copper, iron and zinc in Turkish dietary vegetable oils and olives using electrothermal and flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Acar, O.

    2012-01-01

    The Cd, Pb, Cu, Fe and Zn contents of some edible vegetable oils (soybean, sunflower, flower, nut, corn and olive) and of olives (olive-1, black, green, black crushed with seeds and green crushed with seeds) were determined and evaluated by an electrothermal atomic absorption spectrometer (ETAAS) using an Sc + Ir + NH 4 H 2 PO 4 chemical modifier mixture and flame atomic absorption spectrometer (FAAS) after microwave digestion. The pyrolysis and atomization temperatures of Cd, Pb and Cu in sample solutions with and without the modifier mixture were investigated. The limits of detection (LOD) for analytes found are 0.1, 0.6, 0.9, 15.0 and 12.0 μg L - 1 for Cd, Cu, Pb, Fe and Zn, respectively. The accuracy of the procedure proposed was confirmed by analyzing bovine liver 1577b standard reference material (SRM) and a spiked sample solution. The results of the analytes found were compared with certified and added values. The relative standard deviations of the analytes found were lower than 7% and the percent of recoveries obtained ranges from 96 to 101%. The Sc + Ir + NH 4 H 2 PO 4 mixture proposed was applied for the determination of Cd, Pb and Cu in oils and olives. The results of analytes found in the samples were compared with international and national food quality guidelines as well as with literature values. (Author) 48 refs.

  1. In Vitro Iron Availability from Insects and Sirloin Beef.

    Science.gov (United States)

    Latunde-Dada, Gladys O; Yang, Wenge; Vera Aviles, Mayra

    2016-11-09

    Interest in the consumption of insects (entomophagy) as an alternative environmentally sustainable source of protein in the diet of humans has recently witnessed a surge. Knowledge of the nutrient composition and, in particular, the bioavailability of minerals from insects is currently sparse. This study evaluated the availability of Fe, Ca, Cu, Mg, Mn, and Zn from four commonly eaten insects and compared these to sirloin beef. Soluble iron from the samples was measured by inductively coupled plasma optical emission spectrometry (ICP-OES). Iron bioavailability was determined using an in vitro simulated peptic-pancreatic digestion, followed by measurement of ferritin (a surrogate marker for iron absorption) in Caco-2 cells. Cricket and sirloin beef had comparably higher levels of Fe, Ca, and Mn than grasshopper, meal, and buffalo worms. However, iron solubility was significantly higher from the insect samples than from beef. The complementation of whole-wheat flour with insect or beef protein resulted in overall decreases in mineral content and iron solubility in the composite mixtures. Collectively, the data show that grasshopper, cricket, and mealworms contain significantly higher chemically available Ca, Cu, Mg, Mn, and Zn than sirloin. However, buffalo worms and sirloin exhibited higher iron bioavailability comparable to that of FeSO 4 . Commonly consumed insect species could be excellent sources of bioavailable iron and could provide the platform for an alternative strategy for increased mineral intake in the diets of humans.

  2. Copper absorption from human milk, cow's milk, and infant formulas using a suckling rat model

    International Nuclear Information System (INIS)

    Loennerdal, B.B.; Bell, J.G.; Keen, C.L.

    1985-01-01

    Since copper deficiency is known to occur during infancy, it becomes important to assess copper uptake from various infant diets. The authors have investigated the uptake of copper from human milk, cow's milk, cow's milk formulas, cereal/milk formula and soy formula, compensating for the decay of 64 Cu and using the suckling rat as a model. Radiocopper was added to the diet in trace amounts. Ultracentrifugation, ultrafiltration, and gel filtration were used to show that the added 64 Cu bound to milk fractions and individual binding compounds in a manner analogous to the distribution of native copper, thus validating the use of extrinsically labeled diets. Labeled diets were intubated into 14-day-old suckling rats. Animals were killed after 6 h and tissues removed and counted. Liver copper uptake was 25% from human milk, 23% from cow's milk formula, 18% from cow's milk, 17% from premature (cow's milk based) infant formula, 17% from cereal/milk formula and 10% from soy formula. These results show that the rat pup model may provide a rapid, inexpensive, and sensitive method to assay bioavailability of copper from infant foods

  3. An investigation on the effects of organizational memory and human capital on innovation and absorptive capacity

    Directory of Open Access Journals (Sweden)

    Zahra Mansouri

    2014-06-01

    Full Text Available Innovation is considered as an enabling tool for creating value and sustainable competitive advantage for organizations in dynamic environment of our times along with its ever-increasing complexities. Until innovation in developing countries needs more capital and talent, human capital (HC is a key factor in innovative performance. People are the most important factor of exploitation of foreign knowledge; and knowledge focus in business environment is highly dependent on external information sources in order to develop innovation and improve performance of the company. Studies have shown that although importance level of knowledge is increased, but only 30 percent of existing knowledge is being used in organizations. Expensive but evitable mistakes take place due to information blockage; and the risk of losing knowledge is exceptionally higher when people leave the organization. This study is among the field research. The population includes large manufacturing firms across Khuzestan Province having been active throughout 2013. The data collection tool was a structured questionnaire and sampling is convenience method. The research questionnaire was distributed among a sample of 331 R&D and Human resources Experts selected using simple random sampling. The collected data were analyzed using SPSS and Amos statistical programs. The results indicate that organizational memory had significant impact on ACAP and innovation. Results also showed a significant positive effect of HC on ACAP, but did not support the effect of HC on innovation.

  4. Core-shell iron-iron oxide nanoparticles

    DEFF Research Database (Denmark)

    Kuhn, Luise Theil; Bojesen, A.; Timmermann, L.

    2004-01-01

    We present studies of the magnetic properties of core-shell iron-iron oxide nanoparticles. By combining Mossbauer and X-ray absorption spectroscopy we have been able to measure the change from a Fe3O4-like to a gamma-Fe2O3-like composition from the interface to the surface. Furthermore, we have...

  5. Determination of ultra-trace aluminum in human albumin by cloud point extraction and graphite furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Sun Mei; Wu Qianghua

    2010-01-01

    A cloud point extraction (CPE) method for the preconcentration of ultra-trace aluminum in human albumin prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS) had been developed in this paper. The CPE method was based on the complex of Al(III) with 1-(2-pyridylazo)-2-naphthol (PAN) and Triton X-114 was used as non-ionic surfactant. The main factors affecting cloud point extraction efficiency, such as pH of solution, concentration and kind of complexing agent, concentration of non-ionic surfactant, equilibration temperature and time, were investigated in detail. An enrichment factor of 34.8 was obtained for the preconcentration of Al(III) with 10 mL solution. Under the optimal conditions, the detection limit of Al(III) was 0.06 ng mL -1 . The relative standard deviation (n = 7) of sample was 3.6%, values of recovery of aluminum were changed from 92.3% to 94.7% for three samples. This method is simple, accurate, sensitive and can be applied to the determination of ultra-trace aluminum in human albumin.

  6. Determination of ultra-trace aluminum in human albumin by cloud point extraction and graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sun Mei, E-mail: sunmei@ustc.edu.cn [Hefei National Laboratory for Physical Sciences on Microscale, University of Science and Technology of China, No. 96, Jinzhai Road, Hefei 230026 (China); Wu Qianghua [Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026 (China)

    2010-04-15

    A cloud point extraction (CPE) method for the preconcentration of ultra-trace aluminum in human albumin prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS) had been developed in this paper. The CPE method was based on the complex of Al(III) with 1-(2-pyridylazo)-2-naphthol (PAN) and Triton X-114 was used as non-ionic surfactant. The main factors affecting cloud point extraction efficiency, such as pH of solution, concentration and kind of complexing agent, concentration of non-ionic surfactant, equilibration temperature and time, were investigated in detail. An enrichment factor of 34.8 was obtained for the preconcentration of Al(III) with 10 mL solution. Under the optimal conditions, the detection limit of Al(III) was 0.06 ng mL{sup -1}. The relative standard deviation (n = 7) of sample was 3.6%, values of recovery of aluminum were changed from 92.3% to 94.7% for three samples. This method is simple, accurate, sensitive and can be applied to the determination of ultra-trace aluminum in human albumin.

  7. Determination of ultra-trace aluminum in human albumin by cloud point extraction and graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Sun, Mei; Wu, Qianghua

    2010-04-15

    A cloud point extraction (CPE) method for the preconcentration of ultra-trace aluminum in human albumin prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS) had been developed in this paper. The CPE method was based on the complex of Al(III) with 1-(2-pyridylazo)-2-naphthol (PAN) and Triton X-114 was used as non-ionic surfactant. The main factors affecting cloud point extraction efficiency, such as pH of solution, concentration and kind of complexing agent, concentration of non-ionic surfactant, equilibration temperature and time, were investigated in detail. An enrichment factor of 34.8 was obtained for the preconcentration of Al(III) with 10 mL solution. Under the optimal conditions, the detection limit of Al(III) was 0.06 ng mL(-1). The relative standard deviation (n=7) of sample was 3.6%, values of recovery of aluminum were changed from 92.3% to 94.7% for three samples. This method is simple, accurate, sensitive and can be applied to the determination of ultra-trace aluminum in human albumin. 2009 Elsevier B.V. All rights reserved.

  8. Correlates of anaemia in pregnant urban South Indian women: a possible role of dietary intake of nutrients that inhibit iron absorption.

    Science.gov (United States)

    Samuel, Tinu Mary; Thomas, Tinku; Finkelstein, Julia; Bosch, Ronald; Rajendran, Ramya; Virtanen, Suvi M; Srinivasan, Krishnamachari; Kurpad, Anura V; Duggan, Christopher

    2013-02-01

    To identify correlates of anaemia during the first trimester of pregnancy among 366 urban South Indian pregnant women. Cross-sectional study evaluating demographic, socio-economic, anthropometric and dietary intake data on haematological outcomes. A government maternity health-care centre catering predominantly to the needs of pregnant women from the lower socio-economic strata of urban Bangalore. Pregnant women (n 366) aged ≥18 and ≤40 years, who registered for antenatal screening at ≤14 weeks of gestation. Mean age was 22·6 (sd 3·4) years, mean BMI was 20·4 (sd 3·3) kg/m2 and 236 (64·5 %) of the pregnant women were primiparous. The prevalence of anaemia (Hb poultry (1·94; 1·29, 2·91). Low dietary intake of multiple micronutrients, but higher intakes of nutrients that inhibit Fe absorption such as Ca and P, may help explain high rates of maternal anaemia in India.

  9. The absorption and uptake of recombinant human follicle-stimulating hormone through vaginal subcutaneous injections - a pharmacokinetic study

    Science.gov (United States)

    Hsu, Chao-Chin; Kuo, Hsin-Chih; Hsu, Chao-Tien; Gu, Qing

    2009-01-01

    Background Follicle stimulating hormone (FSH) has been routinely used for ovulation induction. Because of rapid clearance of the hormone, FSH is commonly administered by daily intramuscular or subcutaneous injections in in-vitro fertilization (IVF). To reduce the number of visits to the clinic, an intermittent vaginal injection of rhFSH every 3 days employing the concepts of mesotherapy and uterine first-pass effect was invented and has successfully been applied in women receiving IVF treatment. This study was designed to monitor the pharmacokinetic pattern of rhFSH administered vaginally. Methods Twelve healthy women with regular ovulatory cycles were recruited. All volunteers received gonadotrophin-releasing hormone agonist to suppress pituitary function and were assigned to receive single dose recombinant human FSH (rhFSH, Puregon 300) either using conventional abdominal subcutaneous injection or vaginal subcutaneous injection in a randomized cross-over study. Serum samples were collected at pre- scheduled time intervals after injections of rhFSH to determine immunoreactive FSH levels. Pharmacokinetic parameters characterizing rate [maximal plasma concentrations (Cmax) and time of maximal plasma concentrations (tmax)] and extent [area under the plasma concentration-time curve (AUC) and clearance] of absorption of rhFSH were compared. Results Vaginal injection of rhFSH was well tolerated and no drug-related adverse reaction was noted. Our analysis revealed that tmax was significantly earlier (mean 6.67 versus 13.33 hours) and Cmax was significantly higher (mean 17.77 versus 13.96 IU/L) in vaginal versus abdominal injections. The AUC0-∞ was 1640 versus 1134 IU·hour/L in vaginal and abdominal injections, respectively. Smaller plasma elimination rate constant (0.011 versus 0.016 hour-1), longer mean residence time (106.58 versus 70.47 hours), and slower total body clearance (292.2 versus 400.1 mL/hour) were also found in vaginal injection. Conclusion The vaginal

  10. The absorption and uptake of recombinant human follicle-stimulating hormone through vaginal subcutaneous injections - a pharmacokinetic study

    Directory of Open Access Journals (Sweden)

    Kuo Hsin-Chih

    2009-10-01

    Full Text Available Abstract Background Follicle stimulating hormone (FSH has been routinely used for ovulation induction. Because of rapid clearance of the hormone, FSH is commonly administered by daily intramuscular or subcutaneous injections in in-vitro fertilization (IVF. To reduce the number of visits to the clinic, an intermittent vaginal injection of rhFSH every 3 days employing the concepts of mesotherapy and uterine first-pass effect was invented and has successfully been applied in women receiving IVF treatment. This study was designed to monitor the pharmacokinetic pattern of rhFSH administered vaginally. Methods Twelve healthy women with regular ovulatory cycles were recruited. All volunteers received gonadotrophin-releasing hormone agonist to suppress pituitary function and were assigned to receive single dose recombinant human FSH (rhFSH, Puregon 300 either using conventional abdominal subcutaneous injection or vaginal subcutaneous injection in a randomized cross-over study. Serum samples were collected at pre- scheduled time intervals after injections of rhFSH to determine immunoreactive FSH levels. Pharmacokinetic parameters characterizing rate [maximal plasma concentrations (Cmax and time of maximal plasma concentrations (tmax] and extent [area under the plasma concentration-time curve (AUC and clearance] of absorption of rhFSH were compared. Results Vaginal injection of rhFSH was well tolerated and no drug-related adverse reaction was noted. Our analysis revealed that tmax was significantly earlier (mean 6.67 versus 13.33 hours and Cmax was significantly higher (mean 17.77 versus 13.96 IU/L in vaginal versus abdominal injections. The AUC0-∞ was 1640 versus 1134 IU·hour/L in vaginal and abdominal injections, respectively. Smaller plasma elimination rate constant (0.011 versus 0.016 hour-1, longer mean residence time (106.58 versus 70.47 hours, and slower total body clearance (292.2 versus 400.1 mL/hour were also found in vaginal injection

  11. Direct determination of lead in human urine and serum samples by electrothermal atomic absorption spectrometry and permanent modifiers

    International Nuclear Information System (INIS)

    Andrada, Daniel; Pinto, Frederico G.; Magalhaes, Cristina Goncalves; Nunes, Berta R.; Silva, Jose Bento Borba da; Franco, Milton B.

    2006-01-01

    The object of the present study was the development of alternative methods for the direct determination of lead in undigested samples of human urine and serum by electrothermal atomic absorption spectrometry (ETAAS). Thus, some substances have been investigated to act as chemical modifiers. Volumes of 20 μL of diluted samples, 1 + 1, v/v for urine and 1 + 4, v/v for serum, with HNO 3 1% v/v and 0.02% v/v of cetyl trimethyl ammonium chloride (CTAC) were prepared directly in the autosampler cups and placed into the graphite furnace. For modifiers in solutions 10 μL were used. Pyrolysis and atomization temperature curves were used in all optimizations in the matrixes diluted as exposed. For urine with permanent iridium (500 μg), the best pyrolysis and atomization temperatures were 900 and 1600 deg C, respectively, with a characteristic mass of 12 pg (recommended of 10 pg), with symmetrical absorption pulses and corrected background. Spiked urine samples presented recoveries between 86 and 112% for Ir permanent. The analysis results of certified urine samples are in agreement with certified values (95% of confidence) for two levels of the metal. For serum, good results were obtained with the mixture of Zr+Rh or Ir+Rh as permanent modifiers, with characteristic masses of 9.8 and 8.1 pg, respectively. Recoveries from spiked serum samples varied between 98.6 and 100.1% (Ir+Rh) and between 93.9 and 105.2% (Zr+Rh). In both recovery studies, the relative standard deviation (n=3) was lower than 7%. Calibration for both samples were made with aqueous calibration curves and presented r 2 higher than 0.99. The limits of detection were 0.7 μg L -1 for serum samples, with Zr+Rh permanent, and 1.0 μg L -1 for urine with iridium permanent. (author)

  12. Direct determination of lead in human urine and serum samples by electrothermal atomic absorption spectrometry and permanent modifiers

    Directory of Open Access Journals (Sweden)

    Andrada Daniel

    2006-01-01

    Full Text Available The object of the present study was the development of alternative methods for the direct determination of lead in undigested samples of human urine and serum by electrothermal atomic absorption spectrometry (ET AAS. Thus, some substances have been investigated to act as chemical modifiers. Volumes of 20 µL of diluted samples, 1 + 1, v/v for urine and 1 + 4, v/v for serum, with HNO3 1% v/v and 0.02% v/v of cetil trimethyl ammonium chloride (CTAC were prepared directly in the autosampler cups and placed into the graphite furnace. For modifiers in solutions 10 µL were used. Pyrolysis and atomization temperature curves were used in all optimizations in the matrixes diluted as exposed. For urine with permanent iridium (500 µg, the best pyrolysis and atomization temperatures were 900 and 1600 ºC, respectively, with a characteristic mass of 12 pg (recommended of 10 pg, with symmetrical absorption pulses and corrected background. Spiked urine samples presented recoveries between 86 and 112% for Ir permanent. The analysis results of certified urine samples are in agreement with certified values (95% of confidence for two levels of the metal. For serum, good results were obtained with the mixture of Zr+Rh or Ir+Rh as permanent modifiers, with characteristic masses of 9.8 and 8.1 pg, respectively. Recoveries from spiked serum samples varied between 98.6 and 100.1% (Ir+Rh and between 93.9 and 105.2% (Zr+Rh. In both recovery studies, the relative standard deviation (n=3 was lower than 7%. Calibration for both samples were made with aqueous calibration curves and presented r² higher than 0.99. The limits of detection were 0.7 µg L-1 for serum samples, with Zr+Rh permanent, and 1.0 µg L-1 for urine with iridium permanent.

  13. The Proportion of Anemia Associated with Iron Deficiency in Low, Medium, and High Human Development Index Countries: A Systematic Analysis of National Surveys

    Science.gov (United States)

    Petry, Nicolai; Olofin, Ibironke; Hurrell, Richard F.; Boy, Erick; Wirth, James P.; Moursi, Mourad; Donahue Angel, Moira; Rohner, Fabian

    2016-01-01

    Iron deficiency is commonly assumed to cause half of all cases of anemias, with hereditary blood disorders and infections such as hookworm and malaria being the other major causes. In countries ranked as low, medium, and high by the Human Development Index, we conducted a systematic review of nationally representative surveys that reported the prevalence of iron deficiency, iron deficiency anemia, and anemia among pre-school children and non-pregnant women of reproductive age. Using random effects meta-analyses techniques, data from 23 countries for pre-school children and non-pregnant women of reproductive age was pooled, and the proportion of anemia attributable to iron deficiency was estimated by region, inflammation exposure, anemia prevalence, and urban/rural setting. For pre-school children and non-pregnant women of reproductive age, the proportion of anemia associated with iron deficiency was 25.0% (95% CI: 18.0, 32.0) and 37.0% (95% CI: 28.0, 46.0), respectively. The proportion of anemia associated with iron deficiency was lower in countries where anemia prevalence was >40%, especially in rural populations (14% for pre-school children; 16% for non-pregnant women of reproductive age), and in countries with very high inflammation exposure (20% for pre-school children; 25% for non-pregnant women of reproductive age). Despite large heterogeneity, our analyses suggest that the proportion of anemia associated with iron deficiency is lower than the previously assumed 50% in countries with low, medium, or high Human Development Index ranking. Anemia-reduction strategies and programs should be based on an analysis of country-specific data, as iron deficiency may not always be the key determinant of anemia. PMID:27827838

  14. The Proportion of Anemia Associated with Iron Deficiency in Low, Medium, and High Human Development Index Countries: A Systematic Analysis of National Surveys

    Directory of Open Access Journals (Sweden)

    Nicolai Petry

    2016-11-01

    Full Text Available Iron deficiency is commonly assumed to cause half of all cases of anemias, with hereditary blood disorders and infections such as hookworm and malaria being the other major causes. In countries ranked as low, medium, and high by the Human Development Index, we conducted a systematic review of nationally representative surveys that reported the prevalence of iron deficiency, iron deficiency anemia, and anemia among pre-school children and non-pregnant women of reproductive age. Using random effects meta-analyses techniques, data from 23 countries for pre-school children and non-pregnant women of reproductive age was pooled, and the proportion of anemia attributable to iron deficiency was estimated by region, inflammation exposure, anemia prevalence, and urban/rural setting. For pre-school children and non-pregnant women of reproductive age, the proportion of anemia associated with iron deficiency was 25.0% (95% CI: 18.0, 32.0 and 37.0% (95% CI: 28.0, 46.0, respectively. The proportion of anemia associated with iron deficiency was lower in countries where anemia prevalence was >40%, especially in rural populations (14% for pre-school children; 16% for non-pregnant women of reproductive age, and in countries with very high inflammation exposure (20% for pre-school children; 25% for non-pregnant women of reproductive age. Despite large heterogeneity, our analyses suggest that the proportion of anemia associated with iron deficiency is lower than the previously assumed 50% in countries with low, medium, or high Human Development Index ranking. Anemia-reduction strategies and programs should be based on an analysis of country-specific data, as iron deficiency may not always be the key determinant of anemia.

  15. The Proportion of Anemia Associated with Iron Deficiency in Low, Medium, and High Human Development Index Countries: A Systematic Analysis of National Surveys.

    Science.gov (United States)

    Petry, Nicolai; Olofin, Ibironke; Hurrell, Richard F; Boy, Erick; Wirth, James P; Moursi, Mourad; Donahue Angel, Moira; Rohner, Fabian

    2016-11-02

    Iron deficiency is commonly assumed to cause half of all cases of anemias, with hereditary blood disorders and infections such as hookworm and malaria being the other major causes. In countries ranked as low, medium, and high by the Human Development Index, we conducted a systematic review of nationally representative surveys that reported the prevalence of iron deficiency, iron deficiency anemia, and anemia among pre-school children and non-pregnant women of reproductive age. Using random effects meta-analyses techniques, data from 23 countries for pre-school children and non-pregnant women of reproductive age was pooled, and the proportion of anemia attributable to iron deficiency was estimated by region, inflammation exposure, anemia prevalence, and urban/rural setting. For pre-school children and non-pregnant women of reproductive age, the proportion of anemia associated with iron deficiency was 25.0% (95% CI: 18.0, 32.0) and 37.0% (95% CI: 28.0, 46.0), respectively. The proportion of anemia associated with iron deficiency was lower in countries where anemia prevalence was >40%, especially in rural populations (14% for pre-school children; 16% for non-pregnant women of reproductive age), and in countries with very high inflammation exposure (20% for pre-school children; 25% for non-pregnant women of reproductive age). Despite large heterogeneity, our analyses suggest that the proportion of anemia associated with iron deficiency is lower than the previously assumed 50% in countries with low, medium, or high Human Development Index ranking. Anemia-reduction strategies and programs should be based on an analysis of country-specific data, as iron deficiency may not always be the key determinant of anemia.

  16. Myocardial iron content and mitochondrial function in human heart failure: a direct tissue analysis

    Czech Academy of Sciences Publication Activity Database

    Melenovský, V.; Petrák, J.; Mráček, Tomáš; Beneš, J.; Borlaug, B. A.; Nůsková, Hana; Pluháček, T.; Špatenka, J.; Kovalčíková, Jana; Drahota, Zdeněk; Kautzner, J.; Pirk, J.; Houštěk, Josef

    2017-01-01

    Roč. 19, č. 4 (2017), s. 522-530 ISSN 1388-9842 R&D Projects: GA ČR(CZ) GB14-36804G; GA MZd(CZ) NT14050; GA MŠk(CZ) LQ1604; GA MZd NT14250; GA MŠk(CZ) ED1.1.00/02.0109; GA MZd(CZ) NV16-27496A Institutional support: RVO:67985823 Keywords : heart failure * mitochondria * iron deficiency * bioenergetics * metabolism * reactive oxygen species Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 6.968, year: 2016

  17. Hemodynamic measurements in rat brain and human muscle using diffuse near-infrared absorption and correlation spectroscopies

    Science.gov (United States)

    Yu, Guoqiang; Durduran, Turgut; Furuya, D.; Lech, G.; Zhou, Chao; Chance, Britten; Greenberg, J. H.; Yodh, Arjun G.

    2003-07-01

    Measurement of concentration, oxygenation, and flow characteristics of blood cells can reveal information about tissue metabolism and functional heterogeneity. An improved multifunctional hybrid system has been built on the basis of our previous hybrid instrument that combines two near-infrared diffuse optical techniques to simultaneously monitor the changes of blood flow, total hemoglobin concentration (THC) and blood oxygen saturation (StO2). Diffuse correlation spectroscopy (DCS) monitors blood flow (BF) by measuring the optical phase shifts caused by moving blood cells, while diffuse photon density wave spectroscopy (DPDW) measures tissue absorption and scattering. Higher spatial resolution, higher data acquisition rate and higher dynamic range of the improved system allow us to monitor rapid hemodynamic changes in rat brain and human muscles. We have designed two probes with different source-detector pairs and different separations for the two types of experiments. A unique non-contact probe mounted on the back of a camera, which allows continuous measurements without altering the blood flow, was employed to in vivo monitor the metabolic responses in rat brain during KCl induced cortical spreading depression (CSD). A contact probe was used to measure changes of blood flow and oxygenation in human muscle during and after cuff occlusion or exercise, where the non-contact probe is not appropriate for monitoring the moving target. The experimental results indicate that our multifunctional hybrid system is capable of in vivo and non-invasive monitoring of the hemodynamic changes in different tissues (smaller tissues in rat brain, larger tissues in human muscle) under different conditions (static versus moving). The time series images of flow during CSD obtained by our technique revealed spatial and temporal hemodynamic changes in rat brain. Two to three fold longer recovery times of flow and oxygenation after cuff occlusion or exercise from calf flexors in a

  18. Quantitative analysis of absorption, metabolism, and excretion of benzoxazinoids in humans after the consumption of high- and low-benzoxazinoid diets with similar contents of cereal dietary fibres

    DEFF Research Database (Denmark)

    Jensen, Bettina M; Adhikari, Khem B; Schnoor, Heidi J

    2017-01-01

    PURPOSE: Benzoxazinoids (BXs) are a group of wholegrain phytochemicals with potential pharmacological properties; however, limited information exists on their absorption, metabolism, and excretion in humans. The aim of this study was to investigate the dose-dependent uptake and excretion of dieta...

  19. A mosaic genetic structure of the human population living in the South Baltic region during the Iron Age.

    Science.gov (United States)

    Stolarek, Ireneusz; Juras, Anna; Handschuh, Luiza; Marcinkowska-Swojak, Malgorzata; Philips, Anna; Zenczak, Michal; Dębski, Artur; Kóčka-Krenz, Hanna; Piontek, Janusz; Kozlowski, Piotr; Figlerowicz, Marek

    2018-02-06

    Despite the increase in our knowledge about the factors that shaped the genetic structure of the human population in Europe, the demographic processes that occurred during and after the Early Bronze Age (EBA) in Central-East Europe remain unclear. To fill the gap, we isolated and sequenced DNAs of 60 individuals from Kowalewko, a bi-ritual cemetery of the Iron Age (IA) Wielbark culture, located between the Oder and Vistula rivers (Kow-OVIA population). The collected data revealed high genetic diversity of Kow-OVIA, suggesting that it was not a small isolated population. Analyses of mtDNA haplogroup frequencies and genetic distances performed for Kow-OVIA and other ancient European populations showed that Kow-OVIA was most closely linked to the Jutland Iron Age (JIA) population. However, the relationship of both populations to the preceding Late Neolithic (LN) and EBA populations were different. We found that this phenomenon is most likely the consequence of the distinct genetic history observed for Kow-OVIA women and men. Females were related to the Early-Middle Neolithic farmers, whereas males were related to JIA and LN Bell Beakers. In general, our findings disclose the mechanisms that could underlie the formation of the local genetic substructures in the South Baltic region during the IA.

  20. Covalent heme attachment to the protein in human heme oxygenase-1 with selenocysteine replacing the His25 proximal iron ligand.

    Science.gov (United States)

    Jiang, Yongying; Trnka, Michael J; Medzihradszky, Katalin F; Ouellet, Hugues; Wang, Yongqiang; Ortiz de Montellano, Paul R

    2009-03-01

    To characterize heme oxygenase with a selenocysteine (SeCys) as the proximal iron ligand, we have expressed truncated human heme oxygenase-1 (hHO-1) His25Cys, in which Cys-25 is the only cysteine, in the Escherichia coli cysteine auxotroph strain BL21(DE3)cys. Selenocysteine incorporation into the protein was demonstrated by both intact protein mass measurement and mass spectrometric identification of the selenocysteine-containing tryptic peptide. One selenocysteine was incorporated into approximately 95% of the expressed protein. Formation of an adduct with Ellman's reagent (DTNB) indicated that the selenocysteine in the expressed protein was in the reduced state. The heme-His25SeCys hHO-1 complex could be prepared by either (a) supplementing the overexpression medium with heme, or (b) reconstituting the purified apoprotein with heme. Under reducing conditions in the presence of imidazole, a covalent bond is formed by addition of the selenocysteine residue to one of the heme vinyl groups. No covalent bond is formed when the heme is replaced by mesoheme, in which the vinyls are replaced by ethyl groups. These results, together with our earlier demonstration that external selenolate ligands can transfer an electron to the iron [Y. Jiang, P.R. Ortiz de Montellano, Inorg. Chem. 47 (2008) 3480-3482 ], indicate that a selenyl radical is formed in the hHO-1 His25SeCys mutant that adds to a heme vinyl group.

  1. In-situ Characterization and Mapping of Iron Compounds in Alzheimer's Tissue

    International Nuclear Information System (INIS)

    Collingwood, J.F.; Mikhaylova, A.; Davidson, M.; Batich, C.; Streit, W.J.; Terry, J.; Dobson, J.

    2005-01-01

    There is a well-established link between iron overload in the brain and pathology associated with neurodegeneration in a variety of disorders such as Alzheimer's (AD), Parkinson's (PD) and Huntington's (HD) diseases. This association was first discovered in AD by Goodman in 1953, where, in addition to abnormally high concentrations of iron in autopsy brain tissue, iron has also been shown to accumulate at sites of brain pathology such as senile plaques. However, since this discovery, progress in understanding the origin, role and nature of iron compounds associated with neurodegeneration has been slow. Here we report, for the first time, the location and characterization of iron compounds in human AD brain tissue sections. Iron fluorescence was mapped over a frontal-lobe tissue section from an Alzheimer's patient, and anomalous iron concentrations were identified using synchrotron X-ray absorption techniques at 5 (micro)m spatial resolution. Concentrations of ferritin and magnetite, a magnetic iron oxide potentially indicating disrupted brain-iron metabolism, were evident. These results demonstrate a practical means of correlating iron compounds and disease pathology in-situ and have clear implications for disease pathogenesis and potential therapies.

  2. New insights into iron deficiency and iron deficiency anemia.

    Science.gov (United States)

    Camaschella, Clara

    2017-07-01

    Recent advances in iron metabolism have stimulated new interest in iron deficiency (ID) and its anemia (IDA), common conditions worldwide. Absolute ID/IDA, i.e. the decrease of total body iron, is easily diagnosed based on decreased levels of serum ferritin and transferrin saturation. Relative lack of iron in specific organs/tissues, and IDA in the context of inflammatory disorders, are diagnosed based on arbitrary cut offs of ferritin and transferrin saturation and/or marker combination (as the soluble transferrin receptor/ferritin index) in an appropriate clinical context. Most ID patients are candidate to traditional treatment with oral iron salts, while high hepcidin levels block their absorption in inflammatory disorders. New iron preparations and new treatment modalities are available: high-dose intravenous iron compounds are becoming popular and indications to their use are increasing, although long-term side effects remain to be evaluated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Evaluation of cadmium, lead, copper, iron and zinc in Turkish dietary vegetable oils and olives using electrothermal and flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Acar, Orhan

    2012-10-01

    Full Text Available The Cd, Pb, Cu, Fe and Zn contents of some edible vegetable oils (soybean, sunflower, flower, nut, corn and olive and of olives (olive-1, black, green, black crushed with seeds and green crushed with seeds were determined and evaluated by an electrothermal atomic absorption spectrometer (ETAAS using an Sc + Ir + NH4H2PO4 chemical modifier mixture and flame atomic absorption spectrometer (FAAS after microwave digestion. The pyrolysis and atomization temperatures of Cd, Pb and Cu in sample solutions with and without the modifier mixture were investigated. The limits of detection (LOD for analytes found are 0.1, 0.6, 0.9, 15.0 and 12.0 μg L–1 for Cd, Cu, Pb, Fe and Zn, respectively. The accuracy of the procedure proposed was confirmed by analyzing bovine liver 1577b standard reference material (SRM and a spiked sample solution. The results of the analytes found were compared with certified and added values. The relative standard deviations of the analytes found were lower than 7% and the percent of recoveries obtained ranges from 96 to 101%. The Sc + Ir + NH4H2PO4 mixture proposed was applied for the determination of Cd, Pb and Cu in oils and olives. The results of analytes found in the samples were compared with international and national food quality guidelines as well as with literature values.

    Se han determinado los metales Cd, Cu, Pb, Fe y Zn en aceites vegetales comestibles (soja, girasol, flores, nueces, maíz y aceite de oliva y aceitunas (aceitunas-1, negra, verde, negra machacadas con semillas y verde machacadas con semillas mediante espectrometría de absorción atómica electrotérmica (ETAAS utilizando como modificador químico la mezcla Sc + Ir + NH4H2PO4 y mediante espectrometría de absorción atómica de llama (FAAS tras digestión con microondas. Se estudiaron las temperaturas de pirólisis y atomización para Cd

  4. Determination of tellurium in coal samples by means of graphite furnace atomic absorption spectrometry after coprecipitation with iron(III) hydroxide

    Energy Technology Data Exchange (ETDEWEB)

    Oda, S.; Arikawa, Y. [Japan Womens University, Tokyo (Japan)

    2005-11-01

    A simple and accurate method for the determination of tellurium in coal samples was investigated by the combustion of samples under a high pressure of oxygen and coprecipitation with Fe(OH){sub 3}, followed by a measurement by graphite furnace atomic absorption spectrometry (GF-AAS). About 0.5 g of an accurately weighed ground coal sample and 0.5 g of starch were combusted in an oxygen combustion bomb filled with oxygen to 3 MPa and added with 3 ml of water as an absorbing solution. The formed tellurium trioxide TeOs dissolved in water as TeO{sub 4}{sup 2-}, which was in turn reduced to TeO{sub 3}{sup 2-} by heating. After diluting the above-mentioned solution up to about 50 ml with water, Fe(OH){sub 3} is formed upon adding Fe(NO{sub 3}){sub 3} and sodium hydroxide solutions at pH 8-9 and left standing overnight. After dissolving the precipitate by HCl, the solution was diluted to 10 ml with water and the concentration of tellurium was measured by GF-AAS at a wavelength of 214.3 nm. The standard addition method was employed for the determination of tellurium in real coal samples, because those processes for the formation of tellurium(VI) oxide and coprecipitation with Fe(OH)3 were interfered by matrices. For NIST SRM 1632c, the standard coal sample tellurium content of 0.057 {+-} 0.004 mg kg{sup -1} was in good agreement with the information value of 0.05 mg kg{sup -1} with 7% of RSD in five replicate analyses. The tellurium contents in 20 real coal samples given by Center for Coal Utilization, Japan were also determined. The tellurium contents in these samples were scattered over the narrow range between 0.032 and 0.100 mg kg{sup -1}.

  5. Absorption and transport of deuterium-substituted 2R,4'R,8'R-alpha-tocopherol in human lipoproteins

    International Nuclear Information System (INIS)

    Traber, M.G.; Ingold, K.U.; Burton, G.W.; Kayden, H.J.

    1988-01-01

    Oral administration of a single dose of tri- or hexadeuterium substituted 2R,4'R,8'R-alpha-tocopheryl acetate (d3- or d6-alpha-T-Ac) to humans was used to follow the absorption and transport of vitamin E in plasma lipoproteins. Three hr after oral administration of d3-alpha-T-Ac (15 mg) to 2 subjects, plasma levels of d3-alpha-T were detectable; these increased up to 10 hr, reached a plateau at 24 hr, then decreased. Following administration of d6-alpha-T-Ac (15-16 mg) to 2 subjects, the percentage of deuterated tocopherol relative to the total tocopherol in chylomicrons increased more rapidly than the corresponding percentage in whole plasma. Chylomicrons and plasma lipoproteins were isolated from 2 additional subjects following administration of d3-alpha-T-Ac (140 or 60 mg). The percentage of deuterated tocopherol relative to the total tocopherol increased most rapidly in chylomicrons, then in very low density lipoproteins (VLDL), followed by essentially identical increases in low and high density lipoproteins (LDL and HDL, respectively) and lastly, in the red blood cells. This pattern of appearance of deuterated tocopherol is consistent with the concept that newly absorbed vitamin E is secreted by the intestine into chylomicrons; subsequently, chylomicron remnants are taken up by the liver from which the vitamin E is secreted in VLDL. The metabolism of VLDL in the circulation results in the simultaneous delivery of vitamin E into LDL and HDL

  6. Effects of posture on FDTD calculations of specific absorption rate in a voxel model of the human body

    International Nuclear Information System (INIS)

    Findlay, R P; Dimbylow, P J

    2005-01-01

    A change in the posture of the human body can significantly affect the way in which it absorbs radiofrequency electromagnetic radiation. To study this, an anatomically realistic model of the body has been modified to develop new voxel models in postures other than the standard standing position with arms to the side. These postures were sitting, arms stretched out horizontally to the side and vertically above the head. Finite-difference time-domain (FDTD) calculations of the whole-body averaged specific energy absorption rate (SAR) have been performed from 10 MHz to 300 MHz at a resolution of 4 mm. Calculations show that the effect of a raised arm above the head posture was to increase the value of the whole-body averaged SAR at resonance by up to 35% when compared to the standard, arms by the side position. SAR values, both whole-body averaged and localized in the ankle, were used to derive the external electric field values required to produce the SAR basic restrictions of the ICNIRP guidelines. It was found that, in certain postures, external electric field reference levels alone would not provide a conservative estimate of localized SAR exposure and it would be necessary to invoke secondary reference levels on limb currents to provide compliance with restrictions

  7. Effects of posture on FDTD calculations of specific absorption rate in a voxel model of the human body

    Science.gov (United States)

    Findlay, R. P.; Dimbylow, P. J.

    2005-08-01

    A change in the posture of the human body can significantly affect the way in which it absorbs radiofrequency electromagnetic radiation. To study this, an anatomically realistic model of the body has been modified to develop new voxel models in postures other than the standard standing position with arms to the side. These postures were sitting, arms stretched out horizontally to the side and vertically above the head. Finite-difference time-domain (FDTD) calculations of the whole-body averaged specific energy absorption rate (SAR) have been performed from 10 MHz to 300 MHz at a resolution of 4 mm. Calculations show that the effect of a raised arm above the head posture was to increase the value of the whole-body averaged SAR at resonance by up to 35% when compared to the standard, arms by the side position. SAR values, both whole-body averaged and localized in the ankle, were used to derive the external electric field values required to produce the SAR basic restrictions of the ICNIRP guidelines. It was found that, in certain postures, external electric field reference levels alone would not provide a conservative estimate of localized SAR exposure and it would be necessary to invoke secondary reference levels on limb currents to provide compliance with restrictions.

  8. Effects of posture on FDTD calculations of specific absorption rate in a voxel model of the human body

    Energy Technology Data Exchange (ETDEWEB)

    Findlay, R P; Dimbylow, P J [National Radiological Protection Board, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom)

    2005-08-21

    A change in the posture of the human body can significantly affect the way in which it absorbs radiofrequency electromagnetic radiation. To study this, an anatomically realistic model of the body has been modified to develop new voxel models in postures other than the standard standing position with arms to the side. These postures were sitting, arms stretched out horizontally to the side and vertically above the head. Finite-difference time-domain (FDTD) calculations of the whole-body averaged specific energy absorption rate (SAR) have been performed from 10 MHz to 300 MHz at a resolution of 4 mm. Calculations show that the effect of a raised arm above the head posture was to increase the value of the whole-body averaged SAR at resonance by up to 35% when compared to the standard, arms by the side position. SAR values, both whole-body averaged and localized in the ankle, were used to derive the external electric field values required to produce the SAR basic restrictions of the ICNIRP guidelines. It was found that, in certain postures, external electric field reference levels alone would not provide a conservative estimate of localized SAR exposure and it would be necessary to invoke secondary reference levels on limb currents to provide compliance with restrictions.

  9. Evaluation of the Electromagnetic Power Absorption in Humans Exposed to Plane Waves: The Effect of Breathing Activity

    Directory of Open Access Journals (Sweden)

    Marta Cavagnaro

    2013-01-01

    Full Text Available The safety aspects of the exposure of people to uniform plane waves in the frequency range from 900 MHz to 5 GHz are analyzed. Starting from a human body model available in the literature, representing a man in resting state, two new anatomical models are considered, representing different phases of the respiratory activity: tidal breath and deep breath. These models have been used to evaluate the whole body Specific Absorption Rate (SAR and the 10-g averaged and 1-g averaged SAR. The analysis is performed using a parallel implementation of the finite difference time domain method. A uniform plane wave, with vertical polarization, is used as an incident field since this is the canonical exposure situation used in safety guidelines. Results show that if the incident electromagnetic field is compliant with the reference levels promulgated by the International Commission on Non-Ionizing Radiation Protection and by IEEE, the computed SAR values are lower than the corresponding basic restrictions, as expected. On the other side, when the Federal Communications Commission reference levels are considered, 1-g SAR values exceeding the basic restrictions for exposure at 4 GHz and above are obtained. Furthermore, results show that the whole body SAR values increase passing from the resting state model to the deep breath model, for all the considered frequencies.

  10. Iron distribution in cancer cells following doxorubicin exposure using proton and X-ray synchrotron radiation microprobes

    International Nuclear Information System (INIS)

    Ortega, R.; Deves, G.; Bohic, S.; Simionovici, A.; Menez, B.; Bonnin-Mosbah, M.

    2001-01-01

    Chemical studies have shown that doxorubicin, a well-established anticancer agent, is a powerful iron chelator and the resultant iron-drug complex is an efficient catalyst of the conversion of hydrogen peroxide to the highly reactive hydroxyl radical. However, the intracellular complexation of doxorubicin with iron is still debated. Using nuclear microprobe analysis (NMPA), we previously observed in human ovarian cancer cells exposed to 20 μM iodo-doxorubicin (IDX) that iodine and iron cellular distributions were spatially correlated, suggesting a mechanism of intracellular iron chelation by the anthracycline compound. Because maximal plasma drug concentrations in patients are expected to be around 5 μM, NMPA and X-ray absorption near edge spectroscopy (XANES) experiments for iron speciation analysis were performed on cultured cells exposed to pharmacological doses of 2 μM IDX or doxorubicin

  11. Human and animal health risk assessment of metal contamination in soil and plants from Ait Ammar abandoned iron mine, Morocco.

    Science.gov (United States)

    Nouri, Mohamed; Haddioui, Abdelmajid

    2016-01-01

    The goal of this paper is to investigate metal pollution in food chain and assess the resulting health risks to native citizens in Ait Ammar village. The results showed that cadmium (Cd), lead (Pb), and copper (Cu) concentrations in animal organs were above the metal concentration safety limit. Nevertheless, soils and plants from mining area were contaminated with iron (Fe), chromium (Cr), zinc (Zn), and Cr, Cu, Zn respectively. Cd concentrations in almost animal organs were higher than the acceptable daily upper limit, suggesting human consumption of this livestock meat and offal may pose a health risk. The estimated intake of Pb and Cd for Ait Ammar population could be a cause of concern because it exceeded the Provisional Tolerable Weekly Intake (PTWI) proposed by Joint Expert Committee on Food Additives (JECFA) in this area. Thus, conducting regular periodic studies to assess the dietary intake of mentioned elements are recommended.

  12. Probing the Influence of the Conjugated Structure and Halogen Atoms of Poly-Iron-Phthalocyanine on the Oxygen Reduction Reaction by X-ray Absorption Spectroscopy and Density Functional Theory

    International Nuclear Information System (INIS)

    Peng, Yingxiang; Cui, Lufang; Yang, Shifeng; Fu, Jingjing; Zheng, Lirong; Liao, Yi; Li, Kai; Zuo, Xia; Xia, Dingguo

    2015-01-01

    Metal-phthalocyanine (MPc) macrocyclic catalysts have been perceived as promising alternatives to Pt and Pt-based catalysts for the oxygen reduction reaction (ORR). However, the effect of different MPc molecular structures on the ORR has rarely been reported in depth. Herein, iron-phthalocyanine polymers (poly-FePcs) and multi-walled carbon nanotubes (MWCNTs) composites with different structures were synthesized using microwave method. The relationship between their molecular structure and electrocatalytic activity was fully revealed by density functional theory (DFT) and X-ray fine absorption spectroscopy (XAFS). DFT calculations revealed that the introduction of halogen atoms can increase the ion potential (IP) and the dioxo-binding energy () of the poly-FePcs. Meanwhile, their conjugated structure not only facilitates electronic transmission, but also significantly increases . XAFS analysis indicated that the poly-FePc/MWCNTs composites had a square planar structure and a smaller of phthalocyanine ring (Fe-N 4 structure) skeleton structure radius when a larger conjugated structure or introduced halogen atoms was present. The experimental results suggest that the these changes in properties arising from the different structures of the MPc macrocyclic compounds led to a huge effect on their ORR electrochemical activities, and provide a guide to obtaining promising electrochemical catalysts

  13. Probing the influence of the center atom coordination structure in iron phthalocyanine multi-walled carbon nanotube-based oxygen reduction reaction catalysts by X-ray absorption fine structure spectroscopy

    Science.gov (United States)

    Peng, Yingxiang; Li, Zhipan; Xia, Dingguo; Zheng, Lirong; Liao, Yi; Li, Kai; Zuo, Xia

    2015-09-01

    Three different pentacoordinate iron phthalocyanine (FePc) electrocatalysts with an axial ligand (pyridyl group, Py) anchored to multi-walled carbon nanotubes (MWCNTs) are prepared by a microwave method as high performance composite electrocatalysts (FePc-Py/MWCNTs) for the oxygen reduction reaction (ORR). For comparison, tetracoordinate FePc electrocatalysts without an axial ligand anchored to MWCNTs (FePc/MWCNTs) are assembled in the same way. Ultraviolet-visible spectrophotometry (UV-Vis), Raman spectroscopy (RS), and high-resolution transmission electron microscopy (HRTEM) are used to characterize the obtained electrocatalysts. The electrocatalytic activity of the samples is measured by linear sweep voltammetry (LSV), and the onset potential of all of the FePc-Py/MWCNTs electrocatalysts is found to be more positive than that of their FePc/MWCNTs counterparts. X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) spectroscopy are employed to elucidate the relationship between molecular structure and electrocatalytic activity. XPS indicates that higher concentrations of Fe3+ and pyridine-type nitrogen play critical roles in determining the electrocatalytic ORR activity of the samples. XAFS spectroscopy reveals that the FePc-Py/MWCNTs electrocatalysts have a coordination geometry around Fe that is closer to the square pyramidal structure, a higher concentration of Fe3+, and a smaller phthalocyanine ring radius compared with those of FePc/MWCNTs.

  14. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... the Eunice Kennedy Shriver National Institute of Child Health and Human Development, we are investigating how best to treat premature newborns with low hemoglobin levels. We also are hoping to determine which iron supplements work best to treat iron-deficiency anemia in children ...

  15. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... with the Eunice Kennedy Shriver National Institute of Child Health and Human Development, we are investigating how best to treat premature newborns with low hemoglobin levels. We also are hoping to determine which iron supplements work best to treat iron-deficiency anemia in children ...

  16. Restricted access carbon nanotubes for direct extraction of cadmium from human serum samples followed by atomic absorption spectrometry analysis.

    Science.gov (United States)

    Barbosa, Adriano F; Barbosa, Valéria M P; Bettini, Jefferson; Luccas, Pedro O; Figueiredo, Eduardo C

    2015-01-01

    In this paper, we propose a new sorbent that is able to extract metal ions directly from untreated biological fluids, simultaneously excluding all proteins from these samples. The sorbent was obtained through the modification of carbon nanotubes (CNTs) with an external bovine serum albumin (BSA) layer, resulting in restricted access carbon nanotubes (RACNTs). The BSA layer was fixed through the interconnection between the amine groups of the BSA using glutaraldehyde as cross-linker. When a protein sample is percolated through a cartridge containing RACNTs and the sample pH is higher than the isoelectric point of the proteins, both proteins from the sample and the BSA layer are negatively ionized. Thus, an electrostatic repulsion prevents the interaction between the proteins from the sample on the RACNTs surface. At the same time, metal ions are adsorbed in the CNTs (core) after their passage through the chains of proteins. The Cd(2+) ion was selected for a proof-of-principle case to test the suitability of the RACNTs due to its toxicological relevance. RACNTs were able to extract Cd(2+) and exclude almost 100% of the proteins from the human serum samples in an online solid-phase extraction system coupled with thermospray flame furnace atomic absorption spectrometry. The limits of detection and quantification were 0.24 and 0.80 μg L(-1), respectively. The sampling frequency was 8.6h(-1), and the intra- and inter-day precisions at the 0.80, 15.0, and 30.0 μg L(-1) Cd(2+) levels were all lower than 10.1% (RSD). The recoveries obtained for human blood serum samples fortified with Cd(2+) ranged from 85.0% to 112.0%. The method was successfully applied to analyze Cd(2+) directly from six human blood serum samples without any pretreatment, and the observed concentrations ranged from

  17. Synchrotron speciation data for zero-valent iron nanoparticles: Linear combination fitting table(#6) and figure(#9), and extended x-ray absorption fine structure figure(#10) and table(#7)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data set encompasses a complete analysis of synchrotron speciation data for 5 iron nanoparticle samples (P1, P2, P3, S1, S2, and metallic iron) to include...

  18. Effect of dietary iron source and iron status on iron bioavailability tests in the rat

    International Nuclear Information System (INIS)

    Zhang, D.; Hendricks, D.G.; Mahoney, A.W.

    1986-01-01

    Weanling male rats were made anemic in 7 days by feeding a low iron diet and bleeding. Healthy rats were fed the low iron diet supplemented with ferrous sulfate (29 ppm Fe). Each group was subdivided and fed for 10 days on test diets containing about 29 ppm iron that were formulated with meat:spinach mixtures or meat:soy mixtures to provided 100:0, 75:25, 50:50, 25:75, or 0:100% of the dietary iron from these sources or from a ferrous sulfate diet. After 3 days on the diets all rats were dosed orally with 2 or 5 micro curries of 59 Fe after a 18 hour fast and refeeding for 1.5 hours. Iron status influenced liver iron, carcass iron, liver radio activity and percent of radioactive dose retained. Diet influenced fecal iron and apparent absorption of iron. In iron bioavailability studies assessment methodology and iron status of the test subject greatly influences the estimates of the value of dietary sources of iron

  19. Absorption of arsenic from soil and water by two chard (Beta vulgaris L.) varieties: A potential risk to human health.

    Science.gov (United States)

    Yañez, L M; Alfaro, J A; Bovi Mitre, G

    2018-04-14

    The accumulation of arsenic (As) in vegetables poses a risk of contamination to humans via the food chain. Two chard (var. cicla and var. d'ampuis) crops were grown for 60 days in greenhouses on Aridisol soil, and irrigated with water from Pastos Chicos, Jujuy (Argentina). The soil and water used in the trial presented 49 and 1.44 mg/L As concentration levels, respectively. Total dry biomass (TDB) and total As were determined in soils, roots and leaves. The latter was quantified by atomic absorption spectrometry with hydride generation, and bioconcentration and translocation factors were determined. TDB in var. cicla showed statistically significant differences when the plant was cultivated in control soil and watered with the toxicant (2.04 g), as compared with the treatment without exposure (2.8 g). TDB in var. d'ampuis presented statistically significant differences with respect to that of the control when the plants were grown in soils with As and watered with the toxicant (3.3 g). This variety increased its biomass in the presence of As. In the two Swiss chard varieties evaluated, the largest As accumulation in root and leaves was found when they were cultivated in contaminated soil and watered with distilled water. The presence of the toxicant in the leaves exceeded the limits established by Código Alimentario Argentino, i.e. 0.30 mg/kg. Total target hazard quotient (THQ) values for As were higher than 1, suggesting that consumers would run significant risks when consuming these chard varieties. Furthermore, it was determined that the carcinogenic risk (CR) posed by this type of exposure to As exceeded the acceptable risk level of 1 × 10 -6 . Based on this evidence, we may conclude that consuming chard cultivated on the evaluated site brings about considerable risks to local residents' health. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Effects of environmental pollutants on cellular iron homeostasis and ultimate links to human disease

    Science.gov (United States)

    Chronic disease has increased in the last several decades, and environmental pollutants have been implicated. The magnitude and variety of diseases indicate the malfunctioning of some basic mechanism underlying human health. Environmental pollutants demonstrate a capability to co...

  1. Impact of concentration and rate of intraluminal drug delivery on absorption and gut wall metabolism of verapamil in humans.

    Science.gov (United States)

    Glaeser, Hartmut; Drescher, Siegfried; Hofmann, Ute; Heinkele, Georg; Somogyi, Andrew A; Eichelbaum, Michel; Fromm, Martin F

    2004-09-01

    In humans gut wall metabolism can be quantitatively as important as hepatic drug metabolism in limiting the systemic exposure to drugs after oral administration. However, it has been proposed that the role of gut wall metabolism might be overemphasized, because high luminal drug concentrations would lead to a saturation of gut wall metabolism. Therefore we investigated the impact of concentration and rate of intraluminal drug delivery on absorption (F(abs)) and gastrointestinal extraction (E(GI)) of a luminally administered cytochrome P450 (CYP) 3A4 substrate (verapamil) using a multilumen perfusion catheter in combination with a stable isotope technique. Two 20-cm-long, adjacent jejunal segments were isolated with the multilumen perfusion catheter in 7 subjects. In this study 80 mg of unlabeled verapamil (d0-verapamil 15 min) was infused into one segment over a 15-minute period, 80 mg of 3-fold deuterated verapamil (d3-verapamil 240 min) was administered over a 240-minute period into the other segment, and simultaneously, 5 mg of 7-fold deuterated verapamil (d7-verapamil) was injected intravenously over a 15-minute period. The rate of intraluminal drug delivery had only a modest effect on bioavailability of the verapamil isotopes (after correction for F abs ) (F/F abs d3-verapamil 240 min versus d0-verapamil 15 min, 0.24 +/- 0.10 versus 0.20 +/- 0.09; P d3-verapamil 240 min was 0.50 +/- 0.18 compared with 0.59 +/- 0.14 for d0 -verapamil 15 min ( P d0-verapamil 15 min ) correlated strongly with E GI (d3-verapamil 240 min ) (r = 0.94, P d0-verapamil 15 min /d3-verapamil 240 min (r = 0.62, P =.03). Substantial gut wall metabolism of verapamil occurs in humans and can be predicted from ex vivo data by use of shed enterocytes. The different intraluminal concentrations and rates of intraluminal drug delivery did not lead to a pronounced saturation of intestinal drug metabolism.

  2. 57Fe Moessbauer spectroscopic study of Japanese cedar bark - the variation in chemical states of iron due to influence of human activities

    International Nuclear Information System (INIS)

    Matsuo, Motoyuki; Kobayashi, Takaaki; Singh, T.B.; Tsurumi, Makoto; Ichikuni, Masami

    1992-01-01

    Chemical states of iron have been investigated by 57 Fe Moessbauer technique for the barks of Japanese cedar collected from urban and mountainous area of Japan. The Moessbauer spectra of all outer bark samples show two overlapping doublets and one sextet ascribable to paramagnetic ferrous, paramagnetic ferric and magnetic iron, respectively, whereas an inner bark sample consists only of the two doublets. The bark sample from urban area shows the higher relative amount of magnetic component and the smaller ferrous to ferric ratio. These features of iron species in the bark sample indicate that the bark sample can supply a more effective indicator of human activities than airborne particles collected directly by evaluation with an air sampler. (orig.)

  3. The inhibitory effect of superparamagnetic iron oxide nanoparticle (Ferucarbotran) on osteogenic differentiation and its signaling mechanism in human mesenchymal stem cells

    International Nuclear Information System (INIS)

    Chen, Ying-Chun; Hsiao, Jong-Kai; Liu, Hon-Man; Lai, I-Yin; Yao, Ming; Hsu, Szu-Chun; Ko, Bor-Sheng; Chen, Yao-Chang; Yang, Chung-Shi; Huang, Dong-Ming

    2010-01-01

    Superparamagnetic iron oxide (SPIO) nanoparticles are very useful for monitoring cell trafficking in vivo and distinguish whether cellular regeneration originated from an exogenous cell source, which is a key issue for developing successful stem cell therapies. However, the impact of SPIO labeling on stem cell behavior remains uncertain. Here, we show the inhibitory effect of Ferucarbotran, an ionic SPIO, on osteogenic differentiation and its signaling mechanism in human mesenchymal stem cells. Ferucarbotran caused a dose-dependent inhibition of osteogenic differentiation, abolished the differentiation at high concentration, promoted cell migration, and activated the signaling molecules, β-catenin, a cancer/testis antigen, SSX, and matrix metalloproteinase 2 (MMP2). An iron chelator, desferrioxamine, suppressed all the above Ferucarbotran-induced actions, demonstrating an important role of free iron in the inhibition of osteogenic differentiation that is mediated by the promotion of cell mobilization, involving the activation of a specific signaling pathway.

  4. Adsorptive Iron Removal from Groundwater

    OpenAIRE

    Sharma, S.K.

    2001-01-01

    Iron is commonly present in groundwater worldwide. The presence of iron in the water supply is not harmful to human health, however it is undesirable. Bad taste, discoloration, staining, deposition in the distribution system leading to aftergrowth, and incidences of high turbidity are some of the aesthetic and operational problems associated with iron in water supplies. Iron removal from groundwater is, therefore, a major concern for water supply companies using groundwater sources....

  5. Bioavailability of iron to rats from processed soybean fractions determined by intrinsic and extrinsic labeling techniques

    International Nuclear Information System (INIS)

    Weaver, C.M.; Nelson, N.; Elliott, J.G.

    1984-01-01

    Intrinsic and extrinsic labeling techniques were used to measure iron bioavailability from soybean fractions (isolated soy protein, defatted flour, soy hulls, insoluble material and whey) by iron-depleted and non-iron-depleted rats. As expected, absorption of iron was higher in the iron-depleted than in the non-iron-depleted rats. In the iron-depleted group, significantly more iron was absorbed from soy whey than from other fractions. No other significant difference in iron absorption associated with iron source was observed. The higher absorption rate of iron from whey by the iron-depleted rats probably was related to a lower quantity of food consumed during the test meal by this group. Intrinsic and extrinsic labeling techniques produced similar assessments of bioavailability of iron

  6. Study on bioavailability of dietary iron of women by using activable isotopic tracer and neutron activation analysis techniques

    International Nuclear Information System (INIS)

    Zhang Yangmei; Ni Bangfa; Tian Weizhi; Wang Pingsheng; Cao Lei

    2002-01-01

    The bioavailability of diet iron of 10 healthy young women in Beijing area is studied by using two enriched isotopes 54 Fe and 58 Fe, and neutron activation analysis techniques. The abundance of 54 Fe and 58 Fe is 61.4% and 23.4%, respectively. In additional, the atomic absorption spectrometry is employed to measure total iron in fecal samples. Dysprosium, rarely absorbed by human body, is used to monitor the residence time of tracer isotopes in order to collect the fecal samples completely. The results show that the bioavailability of dietary iron in young women is (14.9 +- 3.9)%

  7. Quantitating Iron in Serum Ferritin by Use of ICP-MS

    Science.gov (United States)

    Smith, Scott M.; Gillman, Patricia L.

    2003-01-01

    A laboratory method has been devised to enable measurement of the concentration of iron bound in ferritin from small samples of blood (serum). Derived partly from a prior method that depends on large samples of blood, this method involves the use of an inductively-coupled-plasma mass spectrometer (ICP-MS). Ferritin is a complex of iron with the protein apoferritin. Heretofore, measurements of the concentration of serum ferritin (as distinguished from direct measurements of the concentration of iron in serum ferritin) have been used to assess iron stores in humans. Low levels of serum ferritin could indicate the first stage of iron depletion. High levels of serum ferritin could indicate high levels of iron (for example, in connection with hereditary hemochromatosis an iron-overload illness that is characterized by progressive organ damage and can be fatal). However, the picture is complicated: A high level of serum ferritin could also indicate stress and/or inflammation instead of (or in addition to) iron overload, and low serum iron concentration could indicate inflammation rather than iron deficiency. Only when concentrations of both serum iron and serum ferritin increase and decrease together can the patient s iron status be assessed accurately. Hence, in enabling accurate measurement of the iron content of serum ferritin, the present method can improve the diagnosis of the patient s iron status. The prior method of measuring the concentration of iron involves the use of an atomic-absorption spectrophotometer with a graphite furnace. The present method incorporates a modified version of the sample- preparation process of the prior method. First, ferritin is isolated; more specifically, it is immobilized by immunoprecipitation with rabbit antihuman polyclonal antibody bound to agarose beads. The ferritin is then separated from other iron-containing proteins and free iron by a series of centrifugation and wash steps. Next, the ferritin is digested with nitric acid

  8. Percutaneous absorption and skin decontamination of PCBs: In vitro studies with human skin and in vivo studies in the rhesus monkey

    International Nuclear Information System (INIS)

    Wester, R.C.; Maibach, H.I.; Bucks, D.A.; McMaster, J.; Mobayen, M.; Sarason, R.; Moore, A.

    1990-01-01

    Knowledge of the entry of polychlorinated biphenyls through the skin into the body and subsequent disposition aids estimation of potential for human health hazard. [14C]Aroclor 1242 and [14C]Aroclor 1254 were separately administered intravenously and topically to rhesus monkeys. Following iv administration, 30-d excretion was 39.4 +/- 5.9% urine and 16.1 +/- 0.8% feces (total 55.5 +/- 5.1%) for Aroclor 1242, and 7.0 +/- 2.2% urine and 19.7 +/- 5.8% feces (total 26.7 +/- 7.5%) for Aroclor 1254. Mineral oil and trichlorobenzene are common PCB cosolvents in transformers. Skin absorption of Aroclor 1242 was 20.4 +/- 8.5% formulated in mineral oil and 18.0 +/- 3.8% in trichlorobenzene (p greater than .05). Absorption of Aroclor 1254 was 20.8 +/- 8.3% in mineral oil and 14.6 +/- 3.6% in trichlorobenzene (p greater than .05). PCBs are thus absorbed through skin, and excretion from the body is slow. Vehicle (trichlorobenzene or mineral oil) did not affect percutaneous absorption. In vitro skin absorption in human cadaver skin did not correlate with in vivo findings. This was due to lack of PCB partition from skin into the water receptor fluid, even with addition of 6% Oleth 20 (Volpo 20) solubilizer. Skin decontamination of PCBs showed soap and water to be as effective as or better than the solvent ethanol, mineral oil, and trichlorobenzene in removing PCBs from skin. There is a dynamic time lapse for PCBs between initial skin contact and skin absorption (irreversible removal). Thus initially most PCBs could be removed from skin, but this ability decreased with time to the point where at 24 h only about 25% of the initial PCB skin dose could be recovered with skin washing

  9. Bioavailability of a new iron source used in the fortification of fluid cow's milk. Importance of its use in children after their nursing

    International Nuclear Information System (INIS)

    Boccio, J.; Zubillaga, M.; Lysionek, A.; Caro, R.; Weill, R.

    2000-01-01

    Iron deficiency anemia is the most prevalent nutritional deficiency in Argentina, particularly among infants under 2 years old. At this age the most efficient way to prevent it is through the daily intake of bioavailable iron in weaning foods. Fluid cow's milk is the most popular weaning food in our country. Nowadays, it is possible to fortify this kind of food with 15 mg of iron per liter by a new technological procedure in which ferrous sulfate is microencapsulated with phospholipids. Therefore at the beginning we studied the absorption of this novel iron fortification compound called SFE-171 in fluid cow's milk in animal models as well as human beings. In both cases we found that the absorption values obtained for iron from SFE-171 were 2 folds higher with regard to the values obtained in the case of ferrous sulfate in cow's milk. In order to determine the importance that this fortified milk has in children iron balance after their nursing, we have to evaluate the iron intake by children near the weaning period. In this way we standardized the methodology to determine the iron content in breast milk and the method to determine the breast milk intake. The first part was performed and the iron concentration in breast milk was 0.56±0.08 μg/mL, the second part was started but the experimental phase has to be done. After that we have to determine the effect of iron-fortified cow's milk has on children iron status. Preliminary results suggest that the iron fortified fluid cow's milk with this source of iron produce an adequate iron balance in weaning children. (author)

  10. Bioavailability of a new iron source used in the fortification of fluid cow's milk. Importance of its use in children after their nursing

    Energy Technology Data Exchange (ETDEWEB)

    Boccio, J; Zubillaga, M; Lysionek, A; Caro, R [Laboratorio de Radioisotopos, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires, Buenos Aires (Argentina); Weill, R [Departamento de Industrias Agrarias, Universidad de Moron, Buenos Aires (Argentina)

    2000-07-01

    Iron deficiency anemia is the most prevalent nutritional deficiency in Argentina, particularly among infants under 2 years old. At this age the most efficient way to prevent it is through the daily intake of bioavailable iron in weaning foods. Fluid cow's milk is the most popular weaning food in our country. Nowadays, it is possible to fortify this kind of food with 15 mg of iron per liter by a new technological procedure in which ferrous sulfate is microencapsulated with phospholipids. Therefore at the beginning we studied the absorption of this novel iron fortification compound called SFE-171 in fluid cow's milk in animal models as well as human beings. In both cases we found that the absorption values obtained for iron from SFE-171 were 2 folds higher with regard to the values obtained in the case of ferrous sulfate in cow's milk. In order to determine the importance that this fortified milk has in children iron balance after their nursing, we have to evaluate the iron intake by children near the weaning period. In this way we standardized the methodology to determine the iron content in breast milk and the method to determine the breast milk intake. The first part was performed and the iron concentration in breast milk was 0.56{+-}0.08 {mu}g/mL, the second part was started but the experimental phase has to be done. After that we have to determine the effect of iron-fortified cow's milk has on children iron status. Preliminary results suggest that the iron fortified fluid cow's milk with this source of iron produce an adequate iron balance in weaning children. (author)

  11. Spatial Distribution of Iron Within the Normal Human Liver Using Dual-Source Dual-Energy CT Imaging.

    Science.gov (United States)

    Abadia, Andres F; Grant, Katharine L; Carey, Kathleen E; Bolch, Wesley E; Morin, Richard L

    2017-11-01

    Explore the potential of dual-source dual-energy (DSDE) computed tomography (CT) to retrospectively analyze the uniformity of iron distribution and establish iron concentration ranges and distribution patterns found in healthy livers. Ten mixtures consisting of an iron nitrate solution and deionized water were prepared in test tubes and scanned using a DSDE 128-slice CT system. Iron images were derived from a 3-material decomposition algorithm (optimized for the quantification of iron). A conversion factor (mg Fe/mL per Hounsfield unit) was calculated from this phantom study as the quotient of known tube concentrations and their corresponding CT values. Retrospective analysis was performed of patients who had undergone DSDE imaging for renal stones. Thirty-seven patients with normal liver function were randomly selected (mean age, 52.5 years). The examinations were processed for iron concentration. Multiple regions of interest were analyzed, and iron concentration (mg Fe/mL) and distribution was reported. The mean conversion factor obtained from the phantom study was 0.15 mg Fe/mL per Hounsfield unit. Whole-liver mean iron concentrations yielded a range of 0.0 to 2.91 mg Fe/mL, with 94.6% (35/37) of the patients exhibiting mean concentrations below 1.0 mg Fe/mL. The most important finding was that iron concentration was not uniform and patients exhibited regionally high concentrations (36/37). These regions of higher concentration were observed to be dominant in the middle-to-upper part of the liver (75%), medially (72.2%), and anteriorly (83.3%). Dual-source dual-energy CT can be used to assess the uniformity of iron distribution in healthy subjects. Applying similar techniques to unhealthy livers, future research may focus on the impact of hepatic iron content and distribution for noninvasive assessment in diseased subjects.

  12. Evaluation of an in vitro faecal degradation method for early assessment of the impact of colonic degradation on colonic absorption in humans.

    Science.gov (United States)

    Tannergren, Christer; Borde, Anders; Boreström, Cecilia; Abrahamsson, Bertil; Lindahl, Anders

    2014-06-16

    The objective of this study was to develop and evaluate an in vitro method to investigate bacterial-mediated luminal degradation of drugs in colon in humans. This would be a valuable tool for the assessment of drug candidates during early drug development, especially for compounds intended to be developed as oral extended release formulations. Freshly prepared faecal homogenate from healthy human volunteers (n=3-18), dog (n=6) and rat (colon and caecal content, n=3) was homogenised with 3.8 parts (w/w) physiological saline under anaerobical conditions. Four model compounds (almokalant, budesonide, ximelagatran and metoprolol) were then incubated (n=3-18) separately in the human faecal homogenate for up to 120min at 37°C. In addition, ximelagatran was also incubated in the faecal or colonic content from dog and rat. The mean (±SD) in vitro half-life for almokalant, budesonide and ximelagatran was 39±1, 68±21 and 26±12min, respectively, in the human faecal homogenate. Metoprolol was found to be stable in the in vitro model. The in vitro degradation data was then compared to literature data on fraction absorbed after direct colon administration in humans. The percentage of drug remaining after 60min of in vitro incubation correlated (R(2)=0.90) with the fraction absorbed from colon in humans. The mean in vitro half-life of ximelagatran was similar in human faeces (26±12min) and rat colon content (34±31min), but significantly (pdegradation in vivo was rapidly degraded in the faecal homogenates as well as quantitatively since a correlation was established between percentage degraded in vitro at 60min and fraction absorbed in the colon for the model drugs, which have no other absorption limiting properties. Also, the method is easy to use from a technical point of view, which suggests that the method is suitable for use in early assessment of colonic absorption of extended release formulation candidates. Further improvement of the confidence in the use of the

  13. Lead and cadmium in human teeth from Jordan by atomic absorption spectrometry: Some factors influencing their concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Alomary, A. [Department of Chemistry, Yarmouk University, Irbid (Jordan)]. E-mail: ahmedalomary1000@hotmail.com; Al-Momani, I.F. [Department of Chemistry, Yarmouk University, Irbid (Jordan); Massadeh, A.M. [Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid (Jordan)

    2006-10-01

    The aim of this study was to measure the concentrations of lead (Pb) and cadmium (Cd) in human teeth and to investigate the affecting factors. Teeth samples (n = 268) were collected from people living in different cities in Jordan including Amman, Zarqa, Al-Mafraq and Irbid and analyzed for Pb and Cd using atomic absorption spectrometry (AAS). A questionnaire was used to gather information on each person, such as age, sex, place where the patient lives, smoking, presence of amalgam fillings inside the mouth, and whether the patient uses toothpaste or not. The mean concentrations of Pb and Cd were 28.91 {mu}g/g and 0.44 {mu}g/g, respectively. The results indicate that there is a clear relation between Pb and Cd concentrations and the presence of amalgam fillings, smoking, and place of living. Pb was sex-dependent, whereas Cd was not. Our results show that Pb and Cd concentrations in samples obtained from Al-Mafraq and Irbid are higher than those obtained from Amman and Zarqa. Pb was highest in Mafraq, whereas Cd was highest in Irbid. The Pb and Cd concentrations in teeth from smokers (means: Pb = 31.89 {mu}g/g, Cd = 0.49 {mu}g/g) were significantly higher than those from nonsmokers (means: Pb = 24.07 {mu}g/g, Cd = 0.37 {mu}g/g). Pb and Cd concentrations in teeth of patients with amalgam fillings (means: Pb = 31.02 {mu}g/g and Cd = 0.52 {mu}g/g) were significantly higher than those from patients without amalgam fillings (means: Pb = 26.87 {mu}g/g and Cd = 0.41 {mu}g/g). Our results show that brushing the teeth daily with toothpaste does not significantly decrease the concentration of both Pb and Cd. The mean concentrations of Pb and Cd do not vary significantly between the ages 20-30, 31-40, and 41-50, but both increased rapidly at age 51-60.

  14. In Vivo Dissolution and Systemic Absorption of Immediate Release Ibuprofen in Human Gastrointestinal Tract under Fed and Fasted Conditions.

    Science.gov (United States)

    Koenigsknecht, Mark J; Baker, Jason R; Wen, Bo; Frances, Ann; Zhang, Huixia; Yu, Alex; Zhao, Ting; Tsume, Yasuhiro; Pai, Manjunath P; Bleske, Barry E; Zhang, Xinyuan; Lionberger, Robert; Lee, Allen; Amidon, Gordon L; Hasler, William L; Sun, Duxin

    2017-12-04

    In vivo drug dissolution in the gastrointestinal (GI) tract is largely unmeasured. The purpose of this clinical study was to evaluate the in vivo drug dissolution and systemic absorption of the BCS class IIa drug ibuprofen under fed and fasted conditions by direct sampling of stomach and small intestinal luminal content. Expanding current knowledge of drug dissolution in vivo will help to establish physiologically relevant in vitro models predictive of drug dissolution. A multilumen GI catheter was orally inserted into the GI tract of healthy human subjects. Subjects received a single oral dose of ibuprofen (800 mg tablet) with 250 mL of water under fasting and fed conditions. The GI catheter facilitated collection of GI fluid from the stomach, duodenum, and jejunum. Ibuprofen concentration in GI fluid supernatant and plasma was determined by LC-MS/MS. A total of 23 subjects completed the study, with 11 subjects returning for an additional study visit (a total of 34 completed study visits). The subjects were primarily white (61%) and male (65%) with an average age of 30 years. The subjects had a median [min, max] weight of 79 [52, 123] kg and body mass index of 25.7 [19.4, 37.7] kg/m 2 . Ibuprofen plasma levels were higher under fasted conditions and remained detectable for 28 h under both conditions. The AUC 0-24 and C max were lower in fed subjects vs fasted subjects, and T max was delayed in fed subjects vs fasted subjects. Ibuprofen was detected immediately after ingestion in the stomach under fasting and fed conditions until 7 h after dosing. Higher levels of ibuprofen were detected in the small intestine soon after dosing in fasted subjects compared to fed. In contrast to plasma drug concentration, overall gastric concentrations remained higher under fed conditions due to increased gastric pH vs fasting condition. The gastric pH increased to near neutrality after feedingbefore decreasing to acidic levels after 7 h. Induction of the fed state reduced systemic

  15. Lead and cadmium in human teeth from Jordan by atomic absorption spectrometry: Some factors influencing their concentrations

    International Nuclear Information System (INIS)

    Alomary, A.; Al-Momani, I.F.; Massadeh, A.M.

    2006-01-01

    The aim of this study was to measure the concentrations of lead (Pb) and cadmium (Cd) in human teeth and to investigate the affecting factors. Teeth samples (n = 268) were collected from people living in different cities in Jordan including Amman, Zarqa, Al-Mafraq and Irbid and analyzed for Pb and Cd using atomic absorption spectrometry (AAS). A questionnaire was used to gather information on each person, such as age, sex, place where the patient lives, smoking, presence of amalgam fillings inside the mouth, and whether the patient uses toothpaste or not. The mean concentrations of Pb and Cd were 28.91 μg/g and 0.44 μg/g, respectively. The results indicate that there is a clear relation between Pb and Cd concentrations and the presence of amalgam fillings, smoking, and place of living. Pb was sex-dependent, whereas Cd was not. Our results show that Pb and Cd concentrations in samples obtained from Al-Mafraq and Irbid are higher than those obtained from Amman and Zarqa. Pb was highest in Mafraq, whereas Cd was highest in Irbid. The Pb and Cd concentrations in teeth from smokers (means: Pb = 31.89 μg/g, Cd = 0.49 μg/g) were significantly higher than those from nonsmokers (means: Pb = 24.07 μg/g, Cd = 0.37 μg/g). Pb and Cd concentrations in teeth of patients with amalgam fillings (means: Pb = 31.02 μg/g and Cd = 0.52 μg/g) were significantly higher than those from patients without amalgam fillings (means: Pb = 26.87 μg/g and Cd = 0.41 μg/g). Our results show that brushing the teeth daily with toothpaste does not significantly decrease the concentration of both Pb and Cd. The mean concentrations of Pb and Cd do not vary significantly between the ages 20-30, 31-40, and 41-50, but both increased rapidly at age 51-60

  16. Calcium absorption

    International Nuclear Information System (INIS)

    Carlmark, B.; Reizenstein, P.; Dudley, R.A.

    1976-01-01

    The methods most commonly used to measure the absorption and retention of orally administered calcium are reviewed. Nearly all make use of calcium radioisotopes. The magnitude of calcium absorption and retention depends upon the chemical form and amount of calcium administered, and the clinical and nutritional status of the subject; these influences are briefly surveyed. (author)

  17. Absorption and biological half-life in humans of intrinsic and extrinsic 54Mn tracers from foods of plant origin

    International Nuclear Information System (INIS)

    Johnson, P.E.; Lykken, G.I.; Korynta, E.D.

    1991-01-01

    Absorption and biological half-life of 54 Mn were measured in adult men and women fed foods labeled intrinsically or extrinsically with 54 Mn. Each subject consumed a series of three test meals consisting of a food labeled intrinsically, a food labeled extrinsically or MnCl 2 (control) served in random order. The foods tested were lettuce, spinach, wheat and sunflower seeds. Lettuce meals and their controls contained 9.65 mumol Mn; other meals contained 22.50 mumol Mn. In addition to the test food or MnCl 2 , each meal consisted of vegetable oil (5 g), salt (NaCl, 0.15 g) and crackers (10 g), which provided 0.55 mumol Mn. There were no differences in percentage of Mn absorption or biological half-life of 54 Mn for any of the intrinsically/extrinsically labeled food pairs. Absorption of 54 Mn from MnCl 2 (8.90%) was greater than from lettuce (5.20%), spinach (3.81%), wheat (2.16%) or sunflower seeds (1.71%), but the biological half-life did not vary with the source of Mn. Absorption of 54 Mn from lettuce was significantly (P less than 0.05) greater than from wheat or sunflower seeds. Although the Mn dose in the test meal was less for lettuce than for the other foods, there was no difference in Mn absorption from MnCl 2 between the subjects fed lettuce and subjects fed other foods. There was no correlation of either 54 Mn absorption or biological half-life with whole blood or plasma Mn

  18. Absorption studies

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    Absorption studies were once quite popular but hardly anyone does them these days. It is easier to estimate the blood level of the nutrient directly by radioimmunoassay (RIA). However, the information obtained by estimating the blood levels of the nutrients is not the same that can be obtained from the absorption studies. Absorption studies are primarily done to find out whether some of the essential nutrients are absorbed from the gut or not and if they are absorbed, to determine how much is being absorbed. In the advanced countries, these tests were mostly done to detect pernicious anaemia where vitamin B 12 is not absorbed because of the lack of the intrinsic factor in the stomach. In the tropical countries, ''malabsorption syndrome'' is quire common. In this condition, several nutrients like fat, folic acid and vitamin B 12 are not absorbed. It is possible to study absorption of these nutrients by radioisotopic absorption studies

  19. From tissue iron retention to low systemic haemoglobin levels, new pathophysiological biomarkers of human abdominal aortic aneurysm

    DEFF Research Database (Denmark)

    Martinez-Pinna, Roxanna; Lindholt, Jes Sanddal; Madrigal-Matute, Julio

    2014-01-01

    Iron deposits are observed in tissue of abdominal aortic aneurysm (AAA) patients, although the underlying mechanisms are not completely elucidated. Therefore we explored circulating markers of iron metabolism in AAA patients, and tested if they could serve as biomarkers of AAA. Increased red bloo...

  20. Effect of insulin catheter wear-time on subcutaneous adipose tissue blood flow and insulin absorption in humans

    DEFF Research Database (Denmark)

    Clausen, Trine Schnedler; Kaastrup, Peter; Stallknecht, Bente

    2009-01-01

    blood flow (ATBF) and absorption of the rapid-acting insulin analog insulin aspart over a period of 4 days. METHODS: Teflon insulin catheters (Medtronic, Minneapolis, MN) were inserted into the