Hemosiderin An EPR study of water-insoluble iron in human and rat liver

EPR spectra of the water-insoluble iron fraction, hemosiderin of human and rat liver are described. The homogenate of freshly prepared perfused rat liver shows a non-heme iron signal at g = 4.3 and a high-spin heme-iron signal around g = 6, whereas the washed and sonicated sample of the insoluble iron fraction shows solely a non-heme iron signal at g = 4.3. This indicates that hemosiderin from rat liver does not contain heme iron.Human-liver preparations from post mortem obtained material show in the homogenates as well as in the washed and sonicated samples an intense high-spin heme iron signal at g = 6.0 and a non-heme iron signal at g = 4.3. A comparative experiment, carried out with “aged” rat liver preparations, reveals the same spectra as with the human preparations. It is concluded that the heme present in the insoluble iron fraction is caused by degradation of hemoglobin in the obduction material, and that heme is not a constituent of the insoluble depot iron.     

Hemosiderin. an EPR study of water-insoluble iron in human and rat liver.

EPR spectra of the water-insoluble iron fraction, hemosiderin of human and rat liver are described. The homogenate of freshly prepared perfused rat liver shows a non-heme iron signal at g=4.3 and a high-spin heme-iron signal around g=6, whereas the washed and sonicated sample of the insoluble iron fraction shows solely a non-heme iron signal at g=4.3. This indicates that hemosiderin from rat liver does not contain heme iron. Human-liver preparations from post mortem obtained material show in the homogenates as well as in the washed and sonicated samples an intense high-spin heme iron signal at g=6.0 and a non-heme iron signal at g=4.3. A comparative experiment, carried out with "aged" rat liver preparations, reveals the same spectra as with the human preparations. It is concluded that that the heme present in the insoluble iron fraction is caused by degradation of hemoglobin in the obduction material, and that heme is not a constituent of the insoluble depot iron.     

Modifications in the human EEG during extralong physical activity

In a single-case study, the effects of very long-lasting physical exercise, namely a 24-h-long ultramarathon, on the human electroencephalogram (EEG) were evaluated. While only effects of relatively short exercise have been reported earlier, we focused on the changes induced by these long-lasting physical requires. EEG was recorded repeatedly using an auditory oddball paradigm, and event-related potentials (ERPs), as well as changes in the current oscillatory brain activity (in particular, event-related desynchronization, ERD), were repeatedly monitored. While an increase in several attention-related ERP parameters was reported for shorter exercises, the results of our study show that cognitive performance-related EEG phenomena slowly decreased throughout the race. The P300 amplitude decreased, and the P300 latency increased with ongoing exercise duration. In addition, the difference between standard and target tones at N200b, as well as the difference in the lower alpha ERD, decreased with time, indicating a reduced automatic stimulus evaluation. Neirofiziologiya/Neurophysiology, Vol. 39, No. 1, pp. 81–87, January–February, 2007.     

Assessment of physical activity of the human body considering the thermodynamic system

Correctly dosed physical activity is the basis of a vital and healthy life, but the measurement of physical activity is certainly rather empirical resulting in limited individual and custom activity recommendations. Certainly, very accurate three-dimensional models of the cardiovascular system exist, however, requiring the numeric solution of the Navier–Stokes equations of the flow in blood vessels. These models are suitable for the research of cardiac diseases, but computationally very expensive. Direct measurements are expensive and often not applicable outside laboratories. This paper offers a new approach to assess physical activity using thermodynamical systems and its leading quantity of entropy production which is a compromise between computation time and precise prediction of pressure, volume, and flow variables in blood vessels. Based on a simplified (one-dimensional) model of the cardiovascular system of the human body, we develop and evaluate a setup calculating entropy production of the heart to determine the intensity of human physical activity in a more precise way than previous parameters, e.g. frequently used energy considerations. The knowledge resulting from the precise real-time physical activity provides the basis for an intelligent human–technology interaction allowing to steadily adjust the degree of physical activity according to the actual individual performance level and thus to improve training and activity recommendations.     

Evaluation of the body iron status of native Canadians

The serum ferritin concentration was measured in 1417 Indians and 310 Inuit aged 1 to 89 years. The subjects were initially selected to produce a representative sample of the entire native population, but the rate of nonresponse was high, and the results reported in this paper are representative only of the people studied.In males the median serum ferritin values increased during early life and tended to plateau after the age of 30 years. In females the median values rose during childhood, tended to plateau during adolescence, increased slightly during the reproductive period, then gradually rose thereafter. Ranges of values were wide in all age groups, reflecting the variations in body iron stores. When compared with the Inuit, the Indians had a significantly higher prevalence of abnormal serum ferritin values.From an analysis of the serum ferritin values in Indians it is probable that iron stores were reduced in approximately 30% of children, 40% of adolescents, 34% of nonpregnant women of reproductive age, 11% of older women and 5% of adult males. The corresponding figures for the Inuit were 15%, 23%, 22%, 6% and 1%. In contrast, iron deficiency anemia was found in only 3% to 4% of native peoples. If “normality” requires more than small amounts of iron stores to meet physiologic needs, the results suggest a high probability of iron deficiency in 20% to 40% of native children, adolescents and nonpregnant women of reproductive age, and in 0% to 10% of other subjects; but if “normality” is defined as adequate iron stores for erythropoiesis the prevalence of iron deficiency was approximately 1% to 2% in children and adolescents, 3% to 5% in women and less than 1% in adult males.     

Relation between lean body mass and thyroid volume in competition rowers before and during intensive physical training.

OBJECTIVE: Lean body mass is a better determinant of thyroid size than body weight as demonstrated in a previous crosssectional study. We now evaluated if intra-individual changes in body composition and especially changes in lean body mass, due to physical training, could give rise to changes in thyroid volume. SUBJECTS AND METHODS: We investigated 17 freshmen (group 1) before and after six months of competition rowing; controls (group II) were 19 senior rowers, already participating in a training program for more than 2 years. RESULTS: In group I body weight (BW; p < 0.01), lean body mass (LBM; p < 0.05), fat weight (FW; p < 0.05), body mass index (BMI; p < 0.01) and thyroid volume (TV; p = 0.08) all decreased; in group II body composition and thyroid volume did not change at all during the 6 months observation period. Whereas serum TSH and T3 did not change, free thyroxine (FT4) concentrations increased slightly in both groups (p < 0.01), presumably caused by the combination of exercise and insufficient energy intake. Taking together all subjects, baseline TV was directly related to BW (r = 0.35, p<0.05), to LBM (r=0.40, p<0.05) and to BMI (r=0.43, p < 0.01) but not to FW (r = - 0.06, NS). The decrease in thyroid volume was related to the decrease in LBM (r = 0.32, p = 0.05), in BW (r = 0.49, p < 0.005), in FW (r = 0.42, p = 0.01) and in BMI (r = 0.53, p = 0.001). CONCLUSIONS: After a six-month period of intensive physical training, changes in thyroid volume correlate directly with changes in body composition.     

EPR study of serum ceruloplasmin and iron transferrin in myocardial infarction.

Electron paramagnetic resonance (EPR) analysis of frozen serum from myocardial infarction patients has been conducted. Signal at g=4.3 was found definitively attributable to iron(III)-transferrin complex. Imcrease of serum ceruloplasmin as compared to normal was confirmed, with a concomitant decrease of iron-transferrin content. A mechanism for such correlated variation is hypothesized.     

An EPR study of myeloperoxidase in human granulocytes.

1. EPR spectra of human granulocytes (4 - 10(8) cells per ml) show an intense high-spin ferric heme signal with rhombic symmetry (gx = 6.90 and gy = 5.07) for the heme group. These g-values are identical to those of partially purified myeloperoxidase and thus the signal is derived from ferric myeloperoxidase. In chicken granulocytes, which contain little or no myeloperoxidase, only an axial type of heme iron signal, weak in intensity, can be detected at g = 6.0. 2. Upon phagocytosis of latex particles by human granulocytes the high-spin heme signal with rhombic symmetry is slowly converted into a signal with axial symmetry (gx = gy = 6.0), showing that the EPR signals of myeloperoxidase in the intact cell can be used to study the involvement of the enzyme in metabolic changes during phagocytosis.     

Serum ferritin,cobalt excretion and body iron status.

Serum ferritin concentration was measured by immunoradiometric assay in 64 subjects. It was closely related to the size of body iron stores measured by hemosiderin content of bone marrow in all subjects and by the deferoxamine test in 10 patients with iron overload. Urinary cobalt excretion, an indirect measure of iron absorption, was inversely related to hemosiderin content of bone marrow in 34 patients aged 18 to 72 with or without liver disease, but this relation did not hold in a group of 20 student volunteers aged 17 to 30, indicating that the test is unreliable in young people. A strong inverse correlation was demonstrated between values for cobalt excretion and serum ferritin in the 34 patients and between those for iron absorption and serum ferritin in the 20 students. Serum ferritin concentration appears to reflect accurately the iron status of the healthy individual but high values in liver disease must be interpreted with caution.     

Taking EPR "snapshots" of the oxidative stress status in human blood

Assessment of oxidative stress status (OSS) in human tissues is still troublesome. Using an innovative EPR-radical-probe we successfully measured the instantaneous concentration of ROS directly in peripheral blood of athletes and normally active workers during 60 min controlled exercise. The probe employed was bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)decandioate, which quantitatively and instantaneously reacts with oxygen-centered radicals (including superoxide) to yield the parent nitroxide, which is sufficiently persistent to be measured by EPR. Our measurements suggest that while at rest normally active individuals may benefit more from antioxidant supplementation than athletes; conversely, during exercise athletes may benefit more from supplementation. Our method allows reliable, quick, and non-invasive quantitative determination of OSS in human peripheral blood.     

Effect of an iron supplement on body iron status and aerobic capacity of young training women

Serum iron deficiency has a high incidence in female athletes. We investigated the effects of a daily oral iron supplement, (160 mg) administered during an intensive 7-week physical training programme, on body iron status, and the maximal aerobic capacity (VO2max) of 13 women (group A) compared to 15 who took a placebo (group B). The subjects were 19 years old. Blood samples were obtained before training began and on days 1, 7, 21 and 42 of training. They were analysed for packed cell volume (PVC) and for haemoglobin (Hb), 2,3-diphosphoglycerate (2,3-DPG), haptoglobin, iron and ferritin concentrations. The VO2max was measured on days 0, 21 and 42 of training. Following 21 days of training Hb, PCV and ferritin were significantly higher (P less than or equal to 0.01) in group A compared to group B. Over the training period Hb rose by 9.3% and 2.4% in groups A and B, respectively. At the end of training 66% of group B exhibited ferritin concentrations below 10 ng.ml-1, while none of group A had such low values. Mean VO2max of group A had increased by 7.5% following 21 days of training (P less than or equal to 0.01) and by 15.3% after 42 days. No appreciable increase in VO2max had occurred in group B by day 21 (significantly lower than VO2max of group A; P less than or equal to 0.05), however by day 42 it had increased by 14.3% (P less than or equal to 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)