Objective: To analyze the rate of erythrocyte iron incorporation and provided guidance for the iron nutrition for prepubertal children. Methods: Fifty-seven prepubertal children of Beijing were involved in this study and each subject was orally administered 3 mg of Fe twice daily to obtain a total of 30 mg Fe after a 5-d period. The stable isotope ratios in RBCs were determined in 14th day, 28th day, 60th day, and 90th day. The erythrocyte incorporation rate in children was calculated using the stable isotope ratios, blood volume and body iron mass. Results: The percentage of erythrocyte Fe incorporation increased starting 14 th day, reached a peak at 60 d (boys: 19.67% ± 0.56%, girls: 21.33% ± 0.59%) and then decreased. The erythrocyte incorporation rates of Fe obtained for girls in 60th day was significantly higher than those obtained for boys ( < 0.0001). Conclusions The oral administration of Fe to children can be used to obtain erythrocyte iron incorporation within 90 d. Prepubertal girls should begin to increase the intake of iron and further studies should pay more attention to the iron status in prepubertal children.
Beijing ; Child ; Erythrocytes ; metabolism ; Female ; Humans ; Iron ; metabolism ; Iron Isotopes ; analysis ; Male ; Mass Spectrometry ; methods

OBJECTIVE: This study is to obtain precise data on iron physiological requirements in Chinese children using single stable isotope tracer technique. METHODS: Thirty boys (10.6 ± 0.2 years) and 27 girls (10.4 ± 0.2 years) were received oral 6 mg ⁵⁷Fe each day for 5 consecutive days. Venous blood samples were subsequently drawn to examine the change of total iron concentration and ⁵⁷Fe abundance at day 0, 14, 28, 60, 90, 180, 360, 450, 540, 630, 720. The iron physiological requirement was calculated by iron loss combined with iron circulation rate once ⁵⁷Fe abundance stabilized in human body. RESULTS: The iron physiological requirement was significantly lower in boys than those values in girls (16.88 ± 7.12 vs. 18.40 ± 8.81 μg/kg per day, P < 0.05). Correspondingly, the values were calculated as 722.46 ± 8.43 μg/day for boys and 708.40 ± 7.55 μg/day for girls, respectively. Considering nearly 10% iron absorption rate, the estimated average iron physiological requirement was 6.0 mg/day in boys and 6.2 mg/day in girls. CONCLUSION This study indicate that iron physiological requirement could require more daily iron intake in girls as compare with the values in boys having the same body weight. These findings would be facilitate to the new revised dietary reference intakes.
Body Weight ; Child ; China ; Female ; Humans ; Iron ; Isotopes ; Male ; Nutritional Status

OBJECTIVETo establish a method for detecting plasma concentration of corn polysaccharide iron complex (CPIC) and investigate its absorption, distribution and elimination in rats.

METHODSUsing radioactivity isotope tracing method, we detected the radioactivity of (59)Fe-CPIC in the plasma of rats at different time points by gavages of 3 doses (28.0, 14.0, and 7.0 mg/kg) (59)Fe-CPIC in SD rats. The pharmacokinetic parameters was obtained using DAS 2.0 program for analysis of tissue distribution and elimination of (59)Fe-CPIC.

RESULTSThe standard curve was linear within the range of 0.14-141 µg/ml (r=0.9999, n=5). The average recovery was 95% with a relative standard deviation no more than 15%. The pharmacokinetic parameters at 3 doses obtained, namely t1/2 and AUC (0-), were 214∓104, 231∓110, and 181∓81 min, and 1986.3∓513.3, 737.0∓467.0, and 315.1∓226.1 mg·min-1·L(-)1, respectively. (59)Fe-CPIC were detected in all the 13 tissues types examined and high radioactivity intensity was found in the gastrointestinal tract, hematogenic organs and other organs rich in blood. (59)Fe-CPIC was eliminated after intragastric administration primarily via the feces in rats.

CONCLUSIONThe method we established is easy and specific, and the pharmacokinetic parameters of (59)Fe-CPIC fit the two- compartment open model.

Administration, Oral ; Animals ; Area Under Curve ; Coordination Complexes ; administration & dosage ; pharmacokinetics ; urine ; Feces ; chemistry ; Female ; Intestinal Absorption ; Iron ; administration & dosage ; pharmacokinetics ; urine ; Iron Radioisotopes ; Male ; Polysaccharides ; administration & dosage ; isolation & purification ; pharmacokinetics ; urine ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tissue Distribution ; Zea mays ; chemistry

Radioiodine is a routine therapy for differentiated thyroid cancers. Non-thyroid cancers can intake radioiodine after transfection of the human sodium iodide symporter (hNIS) gene. The human telomerase reverse transcriptase (hTERT) promoter, an excellent tumor-specific promoter, has potential value for targeted gene therapy of glioma. We used the hTERT promoter to drive the expression of the hNIS and human thyroid peroxidase (hTPO) gene as a primary step for testing the effects of radioiodine therapy on malignant glioma. The U87 and U251 cells were co-transfected with two adenoviral vectors, in which the hNIS gene had been coupled to the hTERT promoter and the hTPO gene had been coupled to the CMV promoter, respectively. Then, we performed Western blot, 125I intake and efflux assays, and clonogenic assay with cancer cells. We also did 99mTc tumor imaging of nude mice models. After co-transfection with Ad-hTERT-hNIS and Ad-CMV-hTPO, glioma cells showed the 125I intake almost 1.5 times higher than cells transfected with Ad-hTERT-hNIS alone. Western blots revealed bands of approximately 70 kDa and 110 kDa, consistent with the hNIS and hTPO proteins. In clonogenic assay, approximately 90% of co-transfected cells were killed, compared to 50% of control cells after incubated with 37 MBq of 131I. These results demonstrated that radioiodine therapy was effective in treating malignant glioma cell lines following induction of tumor-specific iodide intake by the hTERT promoter-directed hNIS expression in vitro. Co-transfected hNIS and hTPO genes can result in increased intake and longer retention of radioiodine. Nude mice harboring xenografts transfected with Ad-hTERT-NIS can take 99mTc scans.
Adenoviridae ; genetics ; Animals ; Autoantigens ; genetics ; metabolism ; Cell Line, Tumor ; Cell Survival ; Cytomegalovirus ; genetics ; Genetic Vectors ; Glioma ; diagnostic imaging ; genetics ; metabolism ; pathology ; Half-Life ; Humans ; Iodide Peroxidase ; genetics ; metabolism ; Iodine Radioisotopes ; metabolism ; Iron-Binding Proteins ; genetics ; metabolism ; Mice ; Mice, Nude ; Promoter Regions, Genetic ; Recombinant Proteins ; genetics ; metabolism ; Symporters ; genetics ; metabolism ; Technetium ; Telomerase ; genetics ; Tomography, Emission-Computed, Single-Photon ; Transfection