Urinary zinc excretion and zinc status of patients with Β-thalassemia major

In this study, zinc status and urinary zinc excretion with and without desferrioxamine (DFO) infusion and the relationship between urinary zinc excretion and renal tubular dysfunction in thalassemia major (TM) patients were investigated. Forty TM patients were given four DFO infusions on alternate days over a 1-wk period prior to the transfusion. On each day that DFO was given, a 24-h urine collection initiated. DFO was omitted for 1-wk before the following transfusion and during the period four 24-h urine collections were performed. Twenty healthy children provided 24-h urine collection as controls. Blood samples were taken on each of two consecutive transfusion days of the patients and from the controls. Urinary zinc excretion was measured and plasma and red blood cell (RBC) zinc analysis were performed by inductively coupled plasma-atomic emission spectrophotometry. UrinaryN-acetyl-Β-D-glucosaminidase (NAG) activity and creatinine were determined in morning urine specimens. The mean plasma zinc concentration was significantly lower in the patients not given DFO compared to the values of the patients given DFO and the control group. The mean RBC zinc concentration (Μmol/g Hb) in the patients (with and without DFO) and the control group were similar. Urinary zinc excretion was significantly higher in the patients receiving DFO compared to the control group, whereas urinary zinc excretion in the patients not given DFO was not different from the controls. Urinary NAG indices (U/g Cr) were significantly higher in the patients compared to controls. Urinary zinc excretion was correlated with the urinary NAG indices.     

Circadian rhythms in blood, urine and gastric acid secretion of presumably healthy volunteers.

The mean conisor technique reveals statistically significant circadian rhythms for serum concentrations of iron, chloride, cortisol, PBI, the fibrinolytic activity of blood, urinary iron excretion and gastric acid secretion in studies covering a 24-h span for presumably healthy subjects. Quantification of these rhythms provides internationally comparable reference values both for the conventional clinical laboratory and for any special chronobiologic applications.     

The tissue disposition and urinary excretion of cadmium, zinc, copper and iron, following repeated parenteral administration of cadmium to rats.

The effect of repeated parenteral administration of cadmium (0.75, 1.5 and 3.0 mg/kg) on tissue disposition and urinary excretion of cadmium, zinc, copper and iron has been studied in the male rat. Cadmium, zinc and copper accumulated in liver and kidney, but the concentration of iron did not alter significantly. The kidney weight relative to body weight showed a dose-related increase in weight of 25--65%. Excretion of cadmium in the urine increased directly with dosage and the increase was most significant when kidney damage had probably occurred. Administration of cadmium also resulted in dose-related increases in the urinary excretion of zinc, copper and iron. The cadmium concentration of blood increased with dosage of cadmium, and the plasma concentrations of zinc and copper were also raised but plasma iron concentration was diminished.     

Human circadian rhythms in temperature, trace metals, and blood variables

The literature supports the concept that circadian changes in body temperature reflect changes in the thermoregulatory set point. We were interested in studying the relationship between the circadian rhythm in body temperature and 24-h variations in plasma concentrations of iron, zinc, circulating leukocyte counts, and plasma interleukin 1 (IL-1) activity. Eight healthy men were studied for two separate 48-h sessions. Rectal temperature, plasma iron and zinc concentrations, plasma IL-1 activity, circulating leukocyte counts, and several other blood variables were monitored. Circadian rhythms in temperature, trace metals, and various leukocyte populations were demonstrated. The 24-h pattern of changes in plasma concentrations of iron and zinc approximate an inverse relationship with rectal temperature. Although we were unable to detect any IL-1 activity in human plasma collected at 4-h intervals, the daily changes in plasma trace metal concentrations and the variations in leukocyte populations may provide indirect evidence for a daily variation in local (e.g., in liver) or central nervous system release of IL-1.     

Validation and Assessment of Three Methods to Estimate 24-h Urinary Sodium Excretion from Spot Urine Samples in Chinese Adults

24-h urinary sodium excretion is the gold standard for evaluating dietary sodium intake, but it is often not feasible in large epidemiological studies due to high participant burden and cost. Three methods—Kawasaki, INTERSALT, and Tanaka—have been proposed to estimate 24-h urinary sodium excretion from a spot urine sample, but these methods have not been validated in the general Chinese population. This aim of this study was to assess the validity of three methods for estimating 24-h urinary sodium excretion using spot urine samples against measured 24-h urinary sodium excretion in a Chinese sample population. Data are from a substudy of the Prospective Urban Rural Epidemiology (PURE) study that enrolled 120 participants aged 35 to 70 years and collected their morning fasting urine and 24-h urine specimens. Bias calculations (estimated values minus measured values) and Bland-Altman plots were used to assess the validity of the three estimation methods. 116 participants were included in the final analysis. Mean bias for the Kawasaki method was -740 mg/day (95% CI: -1219, 262 mg/day), and was the lowest among the three methods. Mean bias for the Tanaka method was -2305 mg/day (95% CI: -2735, 1875 mg/day). Mean bias for the INTERSALT method was -2797 mg/day (95% CI: -3245, 2349 mg/day), and was the highest of the three methods. Bland-Altman plots indicated that all three methods underestimated 24-h urinary sodium excretion. The Kawasaki, INTERSALT and Tanaka methods for estimation of 24-h urinary sodium excretion using spot urines all underestimated true 24-h urinary sodium excretion in this sample of Chinese adults. Among the three methods, the Kawasaki method was least biased, but was still relatively inaccurate. A more accurate method is needed to estimate the 24-h urinary sodium excretion from spot urine for assessment of dietary sodium intake in China.     

Magnesium,Calcium, and Trace Elements Excretion in 24-h Urine

Urine is a clinical specimen often used in medical diagnostics for monitoring of elements concentrations and kidneys function. We determined the contents of magnesium (Mg), calcium (Ca), zinc (Zn), copper (Cu), iron (Fe), lead (Pb), and cadmium (Cd) in 74 samples of 24-h urine (from 46 women and 28 men). The measurements were realized by the atomic absorption spectrometry (AAS) with atomization in the flame (FAAS) and in the graphite furnace (GFAAS). The received results were the subject of statistical analysis including the sex and age of volunteers. Moreover, correlations between the elements and the relationships between age and amounts of excreted elements with urine were tested. We found the statistically significant higher content of Zn in men’s urine than in women^’s one. Moreover, both adult women and men (>18 years) excreted much more Ca in urine in comparison to young subjects. Only in case of Pb the significant positive correlation between its amount in 24-h urine of all donors and age was stated. The correlation analysis has shown the significant positive relationships between Ca–Mg, Ca–Fe, Mg–Fe, Cu–Fe, Cu–Cd, Fe–Cd, and Pb–Cd in total samples of urine. Basing on our results, we concluded that the gender and age of donors may impact on the elemental status of 24-h urine.     

Zinc,copper, and iron nutrition studied with enriched stable isotopes

Enriched stable isotopes were used in nutrition studies of normal, healthy adults to measure zinc, copper, and iron absorption. After obtaining baseline values for zinc, copper, and iron absorption from diets adequate in all nutrients, the effects of age, pregnancy, and deveral dietary variables were studied. Stable isotopes of zinc, copper, and iron were incorporated into diets. Complete fecal samples were collected and the unabsorbed isotopes remaining in the samples were measured by thermal ionization mass spectrometry, the most precise analytical method for the determination of stable mineral isotopes. Stable isotopes were also infused in five young men to evaluate the potential of studying mineral utilization and kinetics with stable isotopes. The results of these studies demonstrate that a number of factors can affect mineral absorption, but the specific effects differ for different minerals. Isotopic enrichments could be measured in urine and blood, so kinetic studies of utilization of essential minerals are now feasible with enriched stable isotopes. Continued use of stable isotopes to determine mineral absorption, combined with stable-isotope studies of mineral utilization, balance data, and biochemical indicators of mineral status, should result in a better understanding of mineral requirements and metabolism under a variety of conditions.     

Measurement of endogenous lithium levels in serum and urine by electrothermal atomic absorption spectrometry: a method with potential clinical applications

A highly sensitive flameless atomic absorption method has been adapted for the determination of endogenous trace lithium levels in serum and urine. With ammonium nitrate as the only matrix modifier, serum levels of Li as low as 0.03 mumol/liter are measured accurately and there is no requirement for standard additions. The need for background correction during analysis was clearly established, and tungsten and Zeeman-effect background corrections were compared. The tungsten correction offered superior sensitivity and linearity of standards. Recoveries in urine and serum average 94.8 +/- 7.7 and 95.3 +/- 6.1% (+/- SD), respectively. The endogenous serum Li levels were 0.16 +/- 0.08 mumol/liter for normal subjects dwelling in the Denver metropolitan area. The mean 24-h excretion rate was 5.24 +/- 1.4 mumol/day. The mean fractional excretion of endogenous Li (clearance Li/clearance creatinine) was 23.2 +/- 3.0%, a value similar to values published for exogenously administered Li and measured by conventional methods.     

Role of some biogenic amines in the pathomechanism of glomerulonephritis. II. Adrenaline, noradrenaline and serotonin in acute serum sickness in rabbits

In acute serum sickness induced with one intravenous dose of bovine serum albumin (BSA) in 40 rabbits the patterns of excretion of adrenaline (A), noradrenaline (NA), serotonin (5HT) and 5-hydroxyindole-acetic acid (5HIAA) were studied in 24-hour urine, and the 5HT level was determined at intervals of three days. The urinary levels of biogenic amines were determined daily. Some rabbits immunized with BSA received also additionally 5HT, reserpine or parachlorphenylalanine (PCPA). Administration of BSA to rabbits caused a significant increase in the excretion of A and NA and a less evident increase in 5HT level in the blood. The greatest correlation with the course of the immune reaction was shown by the increase in NA excretion observed on the 2nd and 3rd days after BSA administration, and then between the 5th and the 12th days of the experiment. Daily subcutaneous injections of 5HT during 15 days caused a significant rise of its level in the blood and urine, and an increase of 5HIAA excretion. After reserpine or PCPA administration a significant decrease of the levels of all these amines was observed. Taking into account the results of histological examination of the kidneys, that is intensification of the inflammatory changes after 5HT administration and evident inhibition of the inflammatory process after administration of reserpine and PCPA it must be accepted that the studied amines have an important role in the pathomechanism of glomerulonephritis in acute serum sickness.     

Effects of Selenium on Liver and Muscle Contents and Urinary Excretion of Zinc,Copper, Iron and Manganese

Selenium is a main component of glutathione peroxidase (GPX), a key antioxidant enzyme. Other elements, such as zinc, copper, manganese and iron, are also involved in the pathogenesis of oxidative damage as well as in other important metabolic pathways. The effects of selenium supplementation on the metabolism of these elements have yield controversial results .The aim of this study is to analyse the effects of selenium supplementation on liver, muscle and urinary excretion of zinc, copper, iron and manganese in a situation of oxidative stress, such as protein deficiency. The experimental design included four groups of adult male Sprague–Dawley rats, which received the Lieber–DeCarli control diet, an isocaloric 2 % protein-containing diet and another similar two groups to which selenomethionine (6 mg/l liquid diet) was added. After sacrifice (5 weeks later), muscle, liver and serum selenium were determined, as well as muscle, liver and urinary zinc, copper, manganese and iron and liver GPX activity and liver malondialdehyde. Selenium addition led to decreased liver copper, increased muscle copper, increased copper excretion and increased liver iron, whereas zinc and manganese parameters were essentially unaltered. Muscle, liver and serum selenium were all significantly correlated with liver GPX activity.     

Role of serum and urinary Tamm-Horsfall protein in the surveillance of kidney transplants

The study of 24-h urinary excretion proves to be quite interesting from a theoretical point of view on account of its topographic origin in the nephron and from a practical point of view to control renal transplant patients with favourable or unfavourable course. In both cases, the results we obtain are in accordance with that of blood creatinine assay and ratio N-acetyl-beta-D-glucosaminidase (NAG)/creatinine in urine. The prolonged study of serum THG concentration confirms the previous data regarding the outcome of renal grafts. Moreover, particularly low concentration rates probably imply the interference of factors such as: renal toxins or anti-THG autoantibodies.     

Interaction between zinc and iron in rats

The importance of interactive effects, of minerals in general, on nutrient requirements is becoming increasingly recognized. The interaction between iron and zinc has not been as widely investigated. The metabolic interrelationships between dietary iron and zinc have been known for years, but some subtle relationships may have gone unrecognized. Because nutrient interactions are not necessarily linear in nature, it may be inadequate to apply linear statistical models to study the interaction between zinc and iron. In this study, we used traditional as well as a nonlinear approach in analyzing experimental results from groups of rats fed a wide range of dietary zinc and iron. Male weanling Sprague-Dawley rats were used in a 5 × 4 factorially arranged experiment. Dietary variables were iron (as ferric citrate) at 4, 12, 24, 48, or 96 μg Fe/g diet and zinc (as zinc carbonate) at 5, 10, 20, or 40 μg Zn/g diet. After 7 wk, hematological parameters were measured and plasma ceruloplasmin and cholesterol were determined. In addition to interactive effects as shown by analysis of variance, the application of log-linear analysis to the experimental data revealed a far broader range of interactions between dietary iron and zinc. As a result of our experiment and its quantitative analysis, we conclude that the interaction between iron and zinc is nutritionally important and that dietary iron affected the response of many blood parameters to dietary zinc. The complete dataset can be found at http://www.gfhnrc.ars.usda.gov/fezn. U.S. Department of Agriculture, Agricultural Research Service, Northern Plains Area is an equal opportunity/affirmative action employer and all agency services are available without discrimination.     

Copper,zinc, and selenium in human blood and urine after injection of sodium 2,3-dimercaptopropane-1-sulfonate: a study on subjects with dental amalgam

This study investigated the effects of a single dose of intravenously administered sodium 2,3-dimercaptopropane-1-sulfonate (DMPS) on the essential elements copper, zinc, and selenium in human blood and urine. The possible role of dental amalgam was also addressed. Eighty individuals, divided in four groups according to the presence or absence of dental amalgam fillings and symptoms self-related to such fillings, were given DMPS (2 mg/kg body wt) and 500 mL Ringer’s acetate intravenously. Urine and blood were collected prior to the injection, and thereafter at intervals over a 24-h period. Cu, Zn, and Se concentrations were determined by atomic absorption spectrometry methods. A statistically significant increase in the concentrations of Cu and Zn in urine was observed 30 and 120 min after the DMPS injection compared to the preinjection concentrations. The concentrations of Se were not affected. The cumulated excretion over 24 h after DMPS injection constitutes only from 0.1% to 0.7% of the body content of these elements. There was no effect of different amalgam statuses on Cu and Zn excretion. We found a temporary decrease (4–7%) in the concentrations of Cu, Zn, and Se in blood 15 and 30 min after DMPS, but this seems to be the result of dilution factors. Administration of a single dose of DMPS does not affect the body stores of the essential elements Cu, Zn, and Se.     

Interaction of mineral elements in sea water and shell of oysters (Crassostrea virginica (Gmelin)) cultured in controlled and natural systems

The interaction is reported of selected chemical elements (cadmium, calcium, copper, iron, magnesium, manganese, strontium, and zinc) in cultured sea water, with soft tissues, prismatic calcite of the right valve, and foliated calcite of right and left valves of genetically similar American oysters, Crassostrea virginica (Gmelin) grown in a natural habitat and in two environmentally controlled experimental systems (flow-through and recycle). The addition of trace elements as algal nutrients in ambient sea water was reflected in higher concentrations of trace metals in shells and soft tissues of oysters grown in experimental systems. Calcium was relatively uniformly distributed in major regions of valves from the three habitats, even though its concentration fluctuated widely in sea water in experimental systems. Magnesium and strontium were most concentrated in valves of oysters grown in the recycle system (magnesium in the prismatic layer of the shell and strontium in the foliated calcite). Iron was uniformly distributed. Cadmium, copper, manganese, and zinc were most concentrated in the prismatic calcite of valves from the flow-through system. In soft tissues, calcium was more concentrated in oysters from experimental systems than in those from the natural habitat. Manganese was about equally distributed in soft tissues from the three habitats, whereas copper and iron were more concentrated in soft tissues in experimental systems than in the natural habitat, and were many times more concentrated in soft tissues than in valves from all three habitats. As concentrations of magnesium, strontium, mangenese, zinc, and cadmium increased in valves in experimental systems, pigmentation of valves decreased. The study confirmed the capacity of oysters to concentrate several elements in their valves as concentration of these elements increased in ambient sea water and disclosed the heterogeneous distribution of these elements in major regions of the valves.     

Effect of alpha-lipoic acid preparations on bilirubin and transferrin levels and ferritin iron and transferrin iron content

The influence of ethylendiamine salt of alpha-lipoic acid on the indices of iron metabolism in patients with occupational pathologies has been studied using quantitative electron spin resonance spectroscopy. In the cases of treatment in the patients suffering from hyperferremia the decrease in transferrin iron concentration in the whole blood and plasma occurs correlating with the enhancement of iron excretion from urine and decline of bilirubin level in serum. We have found that the preparation chelates iron from iron (III)-citrate complex and form stable iron (III) complexes. The conclusion is that the positive effects of lipoic acid preparation in the patients with hyperferremia at least partially could be associated with normalization of iron exchange and reduction in the labile iron pool.     

Nanoselenium Supplementation of Heat-Stressed Broilers: Effects on Performance,Carcass Characteristics,Blood Metabolites,Immune Response,Antioxidant Status,and Jejunal Morphology

Magnesium (Mg) is an essential nutrient as a structural constituent of bone and regulator of >300 enzymes. However, studies on intake and urinary excretion of Mg are limited. The purpose of this study was to evaluate Mg intake and its relation to 24-h urinary excretion in healthy adults. Anthropometric measurements and dietary intake by the 24-h recall method were conducted in 80 adults aged 21–69 (average 44.3) years. Urine was collected for 24 h on the day following the dietary survey. Dietary assessment and 24-h urine collection were repeated 3 days later. Daily intake and urinary excretion of Mg were analyzed using Can-Pro and ICP-OES, respectively. The statistical analysis was conducted using SAS program. Mg intake of the subjects was 319 ± 129 mg/day for men and 277 ± 94 mg/day for women and the proportion of subjects who did not meet the estimated average requirement was 50 and 67.5 % for men and women, respectively. Urinary Mg excretion was 30.3 % of the daily Mg intake. Urinary Mg excretion was not significantly correlated with the daily Mg intake. Korean adults are not meeting the recommended intake of Mg, but its urinary excretion suggests homeostasis is not compromised.     

F2-isoprostane excretion rate and diurnal variation in human urine

8-Iso-PGF2alpha is formed in vivo by non-enzymatic free radical catalysed oxidation of arachidonic acid. Urinary measurement of this compound has previously been shown to reflect the oxidative stress of the body in human and animal studies. To investigate the normal excretion rate and a possible diurnal variation of 8-iso-PGF2alpha excretion in humans urinary samples were collected from ten healthy volunteers of both sexes at different times during a day and as a 24-h urine sample. The samples were analyzed by a newly developed radioimmunoassay with a specific antibody against free 8-iso-PGF2alpha. There was no diurnal variation in the urinary levels of 8-iso-PGF2alpha during the day in this study. Neither was there any statistically significant difference between the 8-iso-PGF2alpha levels at any time of the day or in the morning urine samples compared to the 24-h urine samples. In conclusion, all urine samples collected at any time of the day, preferably a morning urine sample (representative urine from 6-8 hours), can thus be used to obtain a reliable and adequate value of the amount of the 8-iso-PGF2alpha excretion in urine in healthy individuals.     

Blood pressure in young adults as influenced by copper and zinc intake

The relationship of copper and zinc status with blood pressure in young adults was studied (N=59). Copper and zinc status was assessed through analysis of serum, urine, hair, and diet records. Males (N=27) had greater systolic and pulse pressures than females (N=32). Multiple regression analysis suggested that males and higher caloric and dietary copper intakes were the predominant factors associated with higher systolic and diastolic pressures, whereas higher dietary zinc intakes were associated with lower pressures. Higher urine zinc excretion rates and serum zinc concentrations were associated with higher diastolic pressures. The sex variable was the strongest factor affecting pulse pressures, with males having higher pulse pressures. Serum zinc concentrations had an inverse relationship to pulse pressures. The data suggest that the weight/height index and age had a low association with blood pressure in this normotensive sample.     

Difference in 24-Hour Urine Composition between Diabetic and Non-Diabetic Adults without Nephrolithiasis

Background

Diabetic patients are more likely to develop kidney stones than the general population. The underlying mechanisms for this disparity remain to be elucidated. Little is known about the relationship between urine composition and diabetes mellitus in non-stone-forming individuals. We sought to examine the differences in the 24-hour (24-h) urine composition between diabetic and non-diabetic adults who were not stone formers.

Methods

A convenience sample of 538 individuals without a history of nephrolithiasis, gout, hyperparathyroidism, or gastroenteric diseases participated in this study. The 24-h urine profiles of 115 diabetic adults were compared with those of 423 non-diabetic adults. Diabetes was defined by self-reported physician diagnosis or medication use. All participants were non-stone formers confirmed by urinary tract ultrasonography. Participants provided a fasting blood sample and a single 24-h urine collection for stone risk analysis. Student’s t-test was used to compare mean urinary values. Linear regression models were adjusted for age, gender, body mass index, hypertension, fasting serum glucose, serum total cholesterol, estimated creatinine clearance rate and urinary factors.

Results

Univariable analysis showed that the diabetic participants had significantly higher 24-h urine volumes and lower urine calcium and magnesium excretions than non-diabetic participants (all P < 0.05). After multivariate adjustment, no significant differences in 24-h urine composition were observed between diabetic and non-diabetic participants except for a slightly increased 24-h urine volume in diabetic participants (all P > 0.05). The main limitation of this study is that the convenience samples and self-reported data may have been sources of bias.

Conclusion

Our data showed that there were no differences in 24-h urine composition between diabetic and non-diabetic adults who are not stone formers. The reason for it might be the improved glycemic control in diabetic individuals in our study. Therefore, a tighter glycemic control might reduce stone formation in diabetic adults.     

Correlations of Trace Element Levels in the Diet,Blood, Urine,and Feces in the Chinese Male

In order to explore the associations between trace elements in dietary intake and the other three biological media (blood, urine, or feces) and inter-element interactions among the latter, we simultaneously collected 72-h diet duplicates, whole blood, and 72-h urine and feces from 120 free-living healthy males in China. Correlations among the toxic (cadmium [Cd], lead [Pb]), and nutritionally essential (zinc [Zn], copper [Cu], iron [Fe], manganese [Mn], selenium [Se], iodine [I]) elements were evaluated using Spearman rank correlation analysis based on analytical data determined by inductively coupled plasma-mass spectrometry. Dietary Cd intakes were highly correlated with the fecal Cd and blood Cd levels. Inverse correlations were found for Fe–Cd and Fe–Pb in both diet versus blood and diet versus feces. Cd–Zn and Cd–Se were significantly directly correlated in the urine and feces. Cd–Se and Pb–Se were negatively correlated in blood. In addition, there existed an extremely significant association between urinary Se and urinary I. Moreover, the other two highly direct correlations were found for Se–Fe and for I–Fe in urine. Improved knowledge regarding their mutual associations is considered to be of fundamental importance to understand more the complex interrelationships in trace element metabolism.