Effects of training and iron supplementation on iron status of cross-country skiers

We have studied the effects of iron treatment on iron deficient cross-country skiers. Kind and duration of their daily training were also considered. Forty-eight athletes were divided in three balanced groups: Group A received 160 mg ferritinic iron/die, Group B received the same amount of iron and 1 gr of ascorbic acid and Group C was untreated. Blood samples were taken at the start, after two months and four months of supplementation. Hematological and iron status parameters were determined. Average training duration was 80 min a day. Running was the most frequent method of training but also roll and country skiing were commonly used. At the initial sample low serum ferritin values were found in all the three groups (Group A = 23.3 micrograms/l, Group B = 20.9 micrograms/l and Group C = 23.5 micrograms/l). After iron treatment serum ferritin increased in Groups A and B (+67.8% and +63.6% respectively) but was slightly reduced in Group C. Serum iron was unchanged and total iron binding capacity decreased following ferritin increase. Ascorbic acid failed to increase iron absorption in Group B. A significant reduction of haptoglobin (-14% and -9% in Group A and B respectively) was also documented. We conclude that cross-country skiers extensively use running in their training and it may be one of the cause of their poor iron status. Ferritinic iron treatment seems to be effective in replacing iron stores in cross-country skiers who underwent heavy training.     

Silicon instead of iron

The effects of light weapons are now regularly seen on television and are becoming an international issue, particularly regarding their impact on civilians. It is claimed that 80% or more of deaths and injuries in today's wars are civilian; there is no objective evidence for this as little accurate information is available. Recent surveys suggest, however, a proportion of between 35 and 65% ‐ still far too high considering the protection to which civilians are entitled under international humanitarian law. It is proposed the problem arises from twentieth‐century killing power in the hands of individuals with fifteenth‐century discipline and organization.

Recent systematic surveys distinguish between civilian deaths from light weapons in combat and non‐combat situations. A high proportion of combat deaths is due to fragmenting weapons such as mortars targeted on populated areas. Many weapon‐related deaths in non‐combat situations are accidental (cleaning weapons, handling by children during play) and others are related to domestic disputes. The availability and use of weapons also affects civilians indirectly in many ways, such as ill‐health in refugees, psychosocial effects on women and children, and economic and environmental consequences.

A variety of schemes exist to reduce the availability of light weapons and reintegrate their users into society. The international community must extend and make better use of these measures.     

MRI of brain iron

A prominently decreased signal intensity in the globus pallidum, reticular substantia nigra, red nucleus, and dentate nucleus was routinely noted in 150 consecutive individuals on T2-weighted images (SE 2000/100) using a high field strength (1.5 T)MR system. This MR finding correlated closely with the decreased estimated T2 relaxation times and the sites of preferential accumulation of ferric iron using the Perls staining method on normal postmortem brains. The decreased signal intensity on T2-weighted images thus provides an accurate in vivo map of the normal distribution of brain iron. Perls stain and MR studies in normal brain also confirm an intermediate level of iron distribution in the striatum, and still lower levels in the cerebral gray and white matter. In the white matter, iron concentration is (a) absent in the most posterior portion of the internal capsule and optic radiations, (b) higher in the frontal than occipital regions, and (c) prominent in the subcortical "U" fibers, particularly in the temporal lobe. There is no iron in the brain at birth; it increases progressively with aging. Knowledge of the distribution of brain iron should assist in elucidating normal anatomic structures and in understanding neurodegenerative, demyelinating, and cerebrovascular disorders.     

Influence of dietary iron source on measures of iron status among female runners

The purpose of the present investigation was to determine whether female runners who consume a modified vegetarian diet are predisposed to iron deficiency. Two groups of female runners who were matched for age, weight, aerobic capacity, miles run per week, and number of pregnancies were obtained for this study. One group (N = 9) regularly consumed a modified vegetarian diet (MV, less than 100 g red meat.wk-1), while the other group (N = 9) consumed a diet which included red meat (RM). Serum ferritin values were significantly (P less than 0.05) lower for the MV group (X +/- SE, 7.4 +/- 1.4 ng.100 ml-1) than for the RM group (19.8 +/- 4.2 ng.100 ml-1). Total iron binding capacity (TIBC) of the serum was also significantly different between the two groups of subjects (MV, 366.5 +/- 12.2 micrograms.100 ml-1; RM, 327.2 +/- 9.6 micrograms.100 ml-1). While dietary iron intake was comparable for the two groups (MV, 14.7 +/- 2.0 mg.d-1; RM, 14.0 +/- 2.2 mg.d-1, the bioavailability of the dietary iron was significantly different (MV, 0.66 +/- 0.08 mg.d-1; RM, 0.91 +/- 0.10 mg.d-1). As the presence of heme iron (from meat, fish, and poultry) increases the bioavailability of dietary iron, the results of the present investigation suggest that vegetarian athletes have altered iron status due to the form in which their dietary iron is consumed.     

口服与静脉铁剂治疗血液透析患者肾性贫血的疗效比较

目的：比较维持性血液透析患者口服和静脉补铁治疗肾性贫血的疗效和安全性。方法：将29例病情稳定的维持性血透患者随机分为口服组（15例）和静脉组（14例）,观察期6 w,口服组给予力蜚能（含铁150 mg/片）300 mg/d;静脉组于透析后静脉补充科莫菲100 mg/次,总量1 000 mg。检测两组患者治疗前后血红蛋白（Hb）、红细胞压积（Hct）、血清铁蛋白（SF）、血清转铁蛋白饱和度（TSAT）。两组促红素用量为100-150 U/kg,静脉或肌注给药,其他用药不变。结果：治疗后两组患者的上述指标均有显著升高（P〈0.05）,而静脉组升高幅度高于口服组（P〈0.01）;静脉组治疗过程中无副作用发生,口服组有2例轻微胃肠道反应。结论：静脉铁剂和口服铁剂都能有效纠正血液透析患者的铁缺乏,而静脉铁剂较口服铁剂疗效更显著,两者均能显著改善患者肾性贫血状况,不良反应发生率低,安全性好。     

MRI of cardiac iron overload

Transfusion therapy has greatly improved the survival of transfusion dependent thalassemia major (TM) patients; however, the resultant iron load damages tissues including the heart, liver and endocrine organs. Among these, heart complication still remains the leading cause of mortality. Myocardial iron deposition can occur independently of other solid organ involvement; conversely, the heart may be spared despite heavy siderosis in other tissues. Iron chelation treatment diminishes the risk of hemosiderosis; however, the chelation treatment has its own toxicities and might not be available to all patients due to costs. Close monitoring of individual organ iron concentration and function is thus important for optimization of individual patient care. This review outlines the importance and clinical significance of recently available MRI techniques for monitoring cardiac iron load. J. Magn. Reson. Imaging 2012;36:1052–1059. © 2012 Wiley Periodicals Inc.     

Extractable iron in experimental hematomas

Summary The extractable iron and total iron were determined in experimental, subcutaneous hematomas (5 ml blood) of rats after different periods of vital time. The extractable iron was determined from homogenate extract obtained after 24-h incubation with concentrated HCl diluted 1:3 and protein precipitation. For the determination of total iron, the specimens were wet-ashed. The same iron determinations were also made for the corresponding control specimens of the subcutaneous tissue. Extractable iron started to rise over the control values in 2-day-old hematomas, being about 5 times higher after 3 days, about 15 times higher after 7 days, and about 20 times higher after 14 days. The ratio of extractable iron and total iron expressed as percentages was about 1% in 1-h and in 1-day-old hematomas, about 20% in 3-day-old hematomas, about 50% in 7-day-old hematomas, and about 65% in 14-day-old or older hematomas. The effect of autolysis for 3 days at room temperature was studied on 1-h-old hematomas. Extractable iron values were slightly higher in the autolyzed specimens, but the difference was statistically insignificant as compared to specimens taken immediately after death.     

Superparamegnetic iron oxides for MRI

Pharmaceutical iron oxide preparations have been used as MRI contrast agents for a variety of purposes. These agents predominantly decrease T2 relaxation times and therefore cause a decrease in signal intensity of tissues that contain the agent. After intravenous adminstration, dextran-coated iron oxides typically accumulate in phagocytic cells in liver and spleen. Clinical trials have shown that iron oxide increases lesion/liver and lesion/spleen contrast, that more lesions can be depicted than on plain MRI or CT, and that the size threshold for lesion detection decreases. Decreased uptake of iron oxides in liver has been observed in hepatitis and cirrhosis, potentially allowing the assessment of organ function. More recently a variety of novel, target-specific monocrydtalline iron oxides compounds have been used for receptor and immunospecific images. Future development of targeted MRI contrast agents is critical for organ- or tissue-specific quantitative and functional MRI. Correspondence to: R. Weissleder     

The influence of circadian variations in plasma iron on the measure of plasma iron turnover

In 92 cases studied in vivo with ⁵⁹Fe, the variations of plasma iron during the study were measured. Errors in calculation of plasma iron turnover of up to 25% can be made in normosideremic patients if such variations are not taken into account. In hypersideremic patients the variations of plasma iron are low or nil; in hyposideremic patients the slow variations of plasma iron concentration do not alter the rapid slope of radio-iron removal.     

Influence of iron status and iron supplements on natural killer cell activity in trained women runners

Twenty-two trained women runners (.VO2peak 48.1 + 1.2 ml x kg -1 x min -1) were divided into an iron supplement (n = 13) or placebo group (n = 9) based on initial serum ferritin concentration (24.2 +/- 2.9 and 58.5 +/- 4.0 microg x l -1, respectively). Exercise consisted of a 35-min run (80 % .VO2peak) and was performed at week 0 (WK0), after two weeks of intensified training (WK2) and after eight weeks recovery training (WK10). The eight weeks recovery training were concomitant with subjects taking iron supplements or placebo in a double blind fashion. Concentrations of serum ferritin, serum iron and total iron binding capacity were assessed pre-exercise and complete blood count, natural killer cell activity (NKACT), and cell surface markers for CD3+, CD4+, CD3+,CD8+, CD3-, CD16+, CD56+ cells were determined both pre- and post-exercise. Serum ferritin concentrations were significantly (p < 0.05) increased on WK10 compared to WK2 (time effect). NKACT (%lysis) and NK cell number was lower (p < 0.05) at WK0 for supplement (42.9 +/- 1.9 % and 305.5 +/- 15.0 x 10 6 x l -1, respectively) compared to placebo groups (50.9 +/- 2.0 and 406.1 +/- 25.6, respectively). Two weeks of intensified training did not alter indices of host defense. In conclusion, NKACT and NK cell numbers were lower in subjects with greater body mass and lower iron stores (p < 0.05), but were not significantly altered after two weeks of intensified training or when serum ferritin levels increased.     

尿毒症患者口服与静脉补铁疗效对比分析

目的：比较慢性肾功能衰竭（CRF）维持性血液透析伴肾性贫血患者，口服多糖铁复合物与静脉注射右旋糖酐氢氧化铁对改善贫血的疗效及副作用。方法：100例患者随机分为口服组与静脉组，每组50例，皮下注射促红细胞生成素（EPO）100-150单位／kg／周，口服组予力蜚能150mg／d，连续8周;静脉组静脉注射科莫非100-200mg至完成所需剂量。结果：静脉及口服补铁均可使血红蛋白、红细胞压积、血清铁蛋白和转铁饱和度升高，静脉组治疗前后差异有显著性（P〈0．01），口服组Hb、HCT无显著性差异（P〉0．05），SF和TSAT有显著性差异（P〈0．01），两组比较治疗前后差值有显著性差异（P〈0．01）。结论：纠正肾性贫血，在使用EPO的同时，静脉补铁优于口服铁剂。     

MR quantification of hepatic iron concentration

PURPOSE: To evaluate the accuracy of magnetic resonance (MR) imaging in the quantification of hepatic iron concentration. MATERIALS AND METHODS: Between April 1999 and June 2001, 112 patients were recruited prospectively. All had undergone liver biopsy and hepatic iron concentration quantification with spectrophotometry, followed by MR imaging. MR imaging involved use of four gradient-echo sequences and one spin-echo sequence. Signal intensity (SI) was measured on images obtained with each sequence by means of regions of interest placed in the liver and paraspinal muscle to obtain the liver-to-muscle SI ratio. The relationship between hepatic iron concentration and SI ratio for each sequence was analyzed with multiple linear regression. Receiver operating characteristic analysis was performed to find the diagnostic thresholds. RESULTS: Sixty-eight patients had normal hepatic iron levels (<36 micromol/g), 23 had hemosiderosis (36-80 micromol/g), and 21 had hemochromatosis (>80 micromol/g). With all sequences, an inverse linear relationship between iron concentration and SI ratio was apparent. The authors generated a mathematic model to estimate the iron concentrations from MR imaging data (r = 0.937). For estimated concentrations of more than 85 micromol/g, the positive predictive value for hemochromatosis was 100%; for those less than 40 micromol/g, the negative predictive value for hemochromatosis was 100%. For estimated concentrations of more than 58 micromol/g, the positive predictive value for iron overload was 100%; for those less than 20 micromol/g, the negative predictive value for iron overload was 100%. CONCLUSION: MR imaging is a useful and noninvasive diagnostic tool for quantification of hepatic iron concentration.