[Analysis on vitamin B_1 and vitamin B_2 proficiency testing assessment in China disease control and prevention system].

OBJECTIVE: To evaluate the detection ability of vitamin B_1 and vitamin B_(2 )in rice flour in the laboratories of disease control and prevention system, by conducting the proficiency testing(PT)activity. METHODS: Before the vitamin B_1 and vitamin B_2 quality control samples were distributed to the laboratories of disease control and prevention system, the uniformity and stability of samples were analyzed by one-way ANOVO respectively. High performance liquid chromatography(HPLC) method was required to determine vitamin B_1(GB 5009.84-2016: determination of vitamin B_1 in food, first method as reference). HPLC method was also required to determine vitamin B_2(GB 5009.85-2016: determination of vitamin B_2 in food, first method as reference). Robust statistics analysis of proficiency testing result was conducted to evaluate laboratory testing ability through Z score. RESULTS: A total of 43 laboratories completed the proficiency testing. In all of the laboratories participated in the determination of vitamin B_(1 )and vitamin B_2, the total satisfactory rate of vitamin B_1 was 88.4%, while vitamin B_2 was 86.0%. CONCLUSION: The ability of vitamin B_1 and vitamin B_2 detection in disease control and prevention system in China is better than expected, and the testing ability of a few laboratory needs to be improved.

Low selenium intake is associated with postpartum weight retention in Chinese women and impaired physical development of their offspring.

The aim of this study was to investigate the association between daily Se intake and postpartum weight retention (PPWR) among Chinese lactating women, and the impact of their Se nutritional status on infants' physical development. Se contents in breast milk and plasma collected from 264 lactating Chinese women at the 42nd day postpartum were analysed with inductively coupled plasma MS. Daily Se intake was calculated based on plasma Se concentration. The dietary data of 24-h records on three consecutive days were collected. Infant growth status was evaluated with WHO standards by Z-scores. Linear regression analyses and multinomial logistic regression were conducted to examine the impact of Se disequilibrium (including other factors) on PPWR and growth of infants, respectively. The results indicated that: (1) the daily Se intake of the subjects was negatively associated with their PPWR (B = -0·002, 95 % CI - 0·003, 0·000, P = 0·039); (2) both insufficient Se daily intake (B = -0·001, OR 0·999, 95 % CI 0·998, 1·000, P = 0·014) and low level of Se in milk (B = -0·025, OR 0·975, 95 % CI 0·951, 0·999, P = 0·021) had potential associations with their infants' wasting, and low level of Se in milk (B = -0·159, OR 0·853, 95 % CI 0·743, 0·980, P = 0·024) had a significant association with their infants' overweight. In conclusion, the insufficient Se nutritional status of lactating Chinese women was first found as one possible influencing factor of their PPWR as well as low physical development of their offspring.

Breast milk selenocystine as a biomarker for selenium intake in lactating women at differential geographical deficiency risk in China.

BACKGROUND AND OBJECTIVES: A reliable biomarker for optimal selenium (Se) intake in lactating women is not currently available. METHODS AND STUDY DESIGN: Daily dietary Se intake in lactating women was calculated from a 24-hour meal record survey for over 3 days. Se levels in plasma and breast milk were measured through inductively coupled plasma mass spectrometry. Plasma selenoprotein P 1 levels and glutathione peroxidase 3 activity were measured using an enzyme-linked immunosorbent assay. Ultra-performance liquid chromatography-tandem mass spectrometry was used to analyze proteinaceous Se species in enzymatically digested breast milk. RESULTS: Dietary Se intakes of lactating women from Liangshan, Beijing, and Enshi were 41.6±21.2 ng/d, 51.1±22.6 ng/d, and 615±178 ng/d, respectively (p<0.05). The Se levels in the blood and breast milk were significantly associated with the dietary Se intake (p<0.05). The proteinaceous Se species in breast milk were SeMet and SeCys2. The levels of SeMet in the lactating women from Liangshan, Beijing, and Enshi were 3.31±2.44 ng Se/mL, 7.34±3.70 ng Se/mL, and 8.99±9.64 ng Se/mL, while that of SeCys2 were 13.7±12.0 ng Se/mL, 35.6±20.9 ng Se/mL, and 57.4±13.2 ng Se/mL, respectively. Notably, the concentration of SeCys2, the metabolite of unstable SeCys, reached a saturation platform, whereas no similar phenomenon were found for the total Se SeMet from Secontaining proteins. CONCLUSIONS: SeCys2 in breast milk is a potential biomarker for determining the optimal Se intake in lactating women.

[Comparison and analysis of 5 metal elements in serum between laboratories].

OBJECTIVE: To evaluate the ability for the detection of 5 metal elements in serum in the laboratories of disease prevention and control system. METHODS: The samples for calcium, magnesium, iron, copper and zinc detection were distributed to 48 laboratories of disease prevention and control system. Inductively coupled plasma mass spectrometry( ICP-MS) analysis or self-selected determination method were allowed to use during detection for each laboratory. The results were analyzed by robust statistical analysis and Z value was used to evaluate the detection ability. RESULTS: Of the laboratories involved in the study, 40 reported results of metal elements detection. Among them, 29 laboratories had satisfactory results, and 11 laboratories had unsatisfactory or suspicious results. The laboratory pass rate of this inter-laboratory comparison was60. 4%. CONCLUSION: The detection level of calcium, magnesium, iron, copper and zinc in serum in disease prevention and control system is generally satisfactory, but the detection ability of some laboratories needs to be further improved.

NHERF1 regulates actin cytoskeleton organization through modulation of α-actinin-4 stability.

The actin cytoskeleton is composed of a highly dynamic network of filamentous proteins, yet the molecular mechanism that regulates its organization and remodeling remains elusive. In this study, Na(+)/H(+) exchanger regulatory factor (NHERF)-1 loss-of-function and gain-of-function experiments reveal that polymerized actin cytoskeleton (F-actin) in HeLa cells is disorganized by NHERF1, whereas actin protein expression levels exhibit no detectable change. To elucidate the molecular mechanism underlying actin cytoskeleton disorganization by NHERF1, a combined 2-dimensional electrophoresis-matrix-assisted laser desorption/ionization-time of flight mass spectrometry approach was used to screen for proteins regulated by NHERF1 in HeLa cells. α-Actinin-4, an actin cross-linking protein, was identified. Glutathione S-transferase pull-down and coimmunoprecipitation studies showed the α-actinin-4 carboxyl-terminal region specifically interacted with the NHERF1 postsynaptic density 95/disc-large/zona occludens-1 domain. The NHERF1/α-actinin-4 interaction increased α-actinin-4 ubiquitination and decreased its expression levels, resulting in actin cytoskeleton disassembly. Our study identified α-actinin-4 as a novel NHERF1 interaction partner and provided new insights into the regulatory mechanism of the actin cytoskeleton by NHERF1.

[Determination of 13 elements in food by microwave plasma-atomic emission spectrometry].

OBJECTIVE: A novel method for quantitative analysis of multi-elements (Ca, Fe, K, Na, Cu, Mn, Zn, Mg, Ni, Sr, Cr, Cd and Co) in food was established by using microwave plasma-atomic emission spectrometry (MP-AES). METHODS: Samples were digested with HNO3 and H2O2 followed by dilution with ultrapure water to 25 mL (g), and then analyzed directly by MP-AES. RESULTS: In the optimal conditions, the linear calibration curve was established for each element, and the linear regression correlation coefficient was more than 0.9999. The limit of detection (LOD) of these multi-elements varied from 0.04 µg/kg to 3.90 µg/kg. The spiked recovery was between 89.8% and 110.4% . The relative standard deviation of precision measurement was between 1.33% and 3.85%. The accurate and reliable results were obtained for validation of the MP-AES method with food reference material according to the standard reference materials (Nist 1549, Nist 1567, Nist 1568 and Nist 1570) and national standard (GBW08501 and GBW10051), and the measured values were in good agreement with the certified values. CONCLUSION: The established method is accurate, simple, fast, reproducible and environmentally friendly.

[Production effect comparison of SEPP and GPx between HepG2 and Hela cells with different selenocompounds].

OBJECTIVE: To compare the effect of several selenocompounds on the productions of SEPP and GPx in HepG2 and Hela cells. METHODS: The cultured HepG2 and Hela cells were divided into the control, Na2SeO3, SeMet and MeSeCys groups. After adding the selected selenocompounds (with the respective concentration 0.01 and 0.1 µmol/L), the experimental groups were then incubated for 48 h and 72 h. Finally, the cell culture supernatants and homogenates were collected for the SEPP and GPx concentrations detection by a double-antibody sandwich enyme-linked immuno-sorbent-assay (ELISA). RESULTS: The SEPP and GPx concentrations in Hela cells treated with 0.1 µmol/L SeMet and MeSeCys were significantly higher than that in the control group (P < 0.05). The SEPP and GPx concentrations in HepG2 cell treated with 0.1 µmol/L selenocompounds were significantly higher than that in Hela cells (P < 0.05). CONCLUSION: HepG2 cells are more beneficial to the production of selenoproteins than Hela cells.

[Tissue distribution of glucuronidated icaritin metabolite in rats].

OBJECTIVE: To establish an ultra-high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS )method for the quantification of glucuronidated icaritin (GICT), and investigate tissue distribution of GICT in rats following a single intraperitoneal administration. METHODS: Acetonitrile was employed to precipitate protein in tissue homogenate after rat tissues were homogenized. The separation was carried out on a BEH C18 column using a gradient mobile phase of acetonitrile, water, ammonium formate and formic acid. The quantification was achieved by the selected reaction monitoring in the negative electrospray ionization mode. Rat tissues were collected for the quantification of GICT after rats were intraperitoneally administered with ICT at a single dose of 10 mg/kg. RESULTS: The calibration curves were linear over the concentration range of 2-200 ng/ml with the lower limit of quantification of 2 ng/ml. The accuracy values at the levels of 5, 80 and 150 ng/ml fell in the range of 93.2-102.9%, and precisions were within 8.9%. CONCLUSION: The UHPLC-MS/MS method was specific and accurate, suitable for the tissue distribution of GICT. GICT was widely distributed in rat's various tissues, in which the content of GICT remained relatively high in kidney and liver, and GICT was reached the highest in tissues at 8 h.

[Quantitative investigation of glucuronidated icaritin metabolite in rats].

OBJECTIVE: To establish an ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS) method for the simultaneous quantification of icairitin(ICT) and its major metabolite glucuronidated icaritin (GICT), and investigate metabolism of ICT in rats following a single intraperitoneal administration. METHODS: ICT, GICT and an internal standard coumestrol (CMT) were extracted from rat plasma using acetonitrile and separated on a C18 column using a gradient mobile phase of acetonitrile, water, ammonium formate and formic acid. In the negative electrospray ionization mode, selected reaction monitoring of the precursor-product ion transitions of m/z 367.1 --> 297.1 for ICT, 543.3 --> 367.1 for GICT and 267.0 - 211.1 for CMT was used for the quantification. Plasma was collected for the determination of ICT and GICT after rats were intraperitoneally administered with ICT at a single dose of 10 mg/kg. RESULTS: The calibration curves were linear over the concentration range of 0.2 - 20 ng/ml for ICT and 2 -200 ng/ml for GICT with the respective lower limit of quantification at 0.2 and 2 ng/ml. The intra- and inter-day accuracy values fell in the range of 95.1 - 103.7%, and precisions were within 10.3%. Recovery and matrix effect were 89.1 - 92.4% and 93.2 - 104.2%, respectively. CONCLUSION: The UHPLC-MS/MS method was specific and accurate, suitable for the metabolism study of ICT. ICT was rapidly metabolized to GICT in rats.

[Effects of dietary wheat gluten level on decreasing plasma homocysteine concentration in rats].

OBJECTIVE: To investigate the effects of different level of casein and wheat gluten on decreasing plasma homocysteine concentration in rats. METHODS: 48 rats of the Wistar were fed with different level of casein (12.5%, 25% and 50%) and wheat gluten (14.5%, 29% and 58%) diets for 14 days, and they were killed by decapitation to obtain blood and livers was subject to analysis the concentration of homocysteine, cysteine and other amino acids, as well as BHMT and CBS activities. RESULTS: Body weight gain in rats fed wheat gluten dietary was significantly less than casein dietary, but food intake was significantly decreased in wheat gluten group with increasing of the protein content. The plasma homocysteine concentration in rats fed wheat gluten was marketly less than casein, however plasma cysteine concentration in wheat gluten was higher than casein group. CONCLUSION: The effects of wheat gluten on plasma homocysteine concentration are mainly depends on the low contents of methionine and high cysteine content, but the low contents of lyscine and threonine are not ignored. The mainly mechanism is that the increased cysteine concentration promot enzyme activities of homocystein metabolism, and increase the consumption of homocysteine.

[Effects of selenium compounds on proliferation, migration and adhesion of HeLa cells].

OBJECTIVE: To explore the effects of methylseleninic acid (MeSeA), selenomethionine (SeMet) and methylselenocysteine (MeSeCys) on proliferation, migration and adhesion of HeLa cells. METHODS: HeLa cells were cultured and treated with MeSeA, SeMet and MeSeCys for 12 - 72 h respectively. MTT assay, healing assay and in vitro cell Matrigel adhesion assay were used to detect the proliferation, migration and adhesion of HeLa cells. RESULTS: Compared to the control group, the proliferation of HeLa cells was remarkably inhibited by MeSeA (P <0. 01). The migration of HeLa cells in MeSeA group was inhibited by 34% (P < 0. 05) and 26% (P < 0. 05) in 4 h and 8 h, respectively. However, the migration of HeLa cells with inhibitions of 18% and 13% was in SeMet group in 4 h and 8 h. The inhibitions of HeLa cell migration in MeSeCys group was 28% (P < 0.05) and 5% in 4 h and 8 h, respectively. In addition, the adhesive function of HeLa cells in the MeSeA group, the SeMet group as well as the MeSeCys group were inhibited by 36% (P < 0. 01), 25% and 49% (P < 0. 01). CONCLUSION: The proliferation and migration of HeLa cell were effectively inhibited by MeSeA, while the adhesive function of HeLa cell was remarkably inhibited by MeSeCys.

[Betaine-enriched beet suppresses hyperhomocysteinemia induced by choline deficiency in rats].

OBJECTIVE: To investigate the dose-dependent effects of beet powder supplementation on hyperhomocysteinemia induced by choline deprivation in rats. Methods 48 rats of the Wistar were fed 25% soybean protein diet (25S), choline deprivation in 25S diets (25SCD) with different betaine levels (0. 05% and 0. 1%) and beet powder levels (4. 12% and 8. 24%) corresponds to betaine levels for 10 days, and they were killed by decapitation to obtain blood and livers was subject to analysis the concentration of homocysteine, cysteine and other amino acids, as well as BHMT and CBS activities. RESULTS: The homocysteine concentration was increased from (11. 8 ± 0. 4) µmol/L to (33. 2 ± 0. 6) µmol/L by choline deprived - 25S diets (P < 0. 05). The choline deprivation-induced enhancement of plasma homocysteine concentration in rats fed 25S diet was significantly suppressed by 0. 10% betaine or 8. 24% beet in a dose dependent manner. Supplementation with betaine or beet significant increased hepatic BHMT activity. CONCLUSION: The results indicated that betaine or beet could completely suppress the hyperhomocysteinemia induced by choline deficiency resulting from stimulating the homocysteine removal by both remethylation and cystathionine formation.

[Inhibition of antisense VEGF gene on the growth of glioma cells BT325].

OBJECTIVE: To investigate the inhibitory effect of antisense VEGF gene on growth of human glioma BT325 and induced apoptosis in cells. METHODS: The pcDNA3.1/anti-VEGF eukaryotic expression vector was constructed and transfected into human glioma BT325. The ELISA assay was used to assess the expression of VEGF gene. Soft agar colony formation, MTT assay and electron microscope were used to evaluate the proliferation, apoptosis and the morphological changes of BT325. RESULTS: Compared with a control group, the level of VEGF expression was significantly decreased and was almost completely suppressed. The amount in soft agar colony at vector group and antisense VEGF gene group were 21 and 2, respectively. The growth of BT325 was significantly inhibited to 38.23% and resulted in the apoptotic morphology by antisense VEGF gene under electron microscope, compared to vector group. CONCLUSION: Antisense VEGF gene inhibited the growth and proliferation, induced cell apoptosis, played an efficient role of anti-cancer in BT325 cells.

Pseudoxanthomonas wuyuanensis sp. nov., isolated from saline-alkali soil.

A bacterium, designated XC21-2(T), was isolated from a saline-alkaline soil sample from China. Cells were Gram-stain-negative, rod-shaped and motile and grew optimally at 35-37 °C, pH 6.0-7.0 and in the presence of 0.5% (w/v) NaCl. Growth occurred in the range pH 5.5-9.0 and in the presence of up to 4 % (w/v) NaCl. The major cellular fatty acids were iso-C15 : 0, iso-C16 : 0 and iso-C17 : 1ω9c. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an uncharacterized amino-group-containing polar lipid. The major quinone was ubiquinone 8 (Q-8) and the G+C content of the genomic DNA was 66.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain XC21-2(T) formed a tight phylogenetic lineage with Pseudoxanthomonas dokdonensis KCTC 12543(T) within the genus Pseudoxanthomonas and was most closely related to P. dokdonensis KCTC 12543(T) and P. mexicana ATCC 700993(T), with 97.9 and 97.5 % 16S rRNA gene sequence similarity, respectively. On the basis of the unique physiological profile of the isolate and its phylogenetic divergence from known species, strain XC21-2(T) represents a novel species within the genus Pseudoxanthomonas, for which the name Pseudoxanthomonas wuyuanensis sp. nov. is proposed. The type strain is XC21-2(T) ( = CGMCC 1.10978(T) = KCTC 23877(T)).

Stabilization of the angiotensin-(1-7) receptor Mas through interaction with PSD95.

The functions and signalling mechanisms of the Ang-(1-7) [angiotensin-(1-7)] receptor Mas have been studied extensively. However, less attention has been paid to the intracellular regulation of Mas protein. In the present study, PSD95 (postsynaptic density 95), a novel binding protein of Mas receptor, was identified, and their association was characterized further. Mas specifically interacts with PDZ1-2, but not the PDZ3, domain of PSD95 via Mas-CT (Mas C-terminus), and the last four amino acids [ETVV (Glu-Thr-Val-Val)] of Mas-CT were determined to be essential for this interaction, as shown by GST pull-down, co-immunoprecipitation and confocal co-localization experiments. Gain-of-function and loss-of-function studies indicated that PSD95 enhanced Mas protein expression by increasing the stabilization of the receptor. Mas degradation was robustly inhibited by the proteasome inhibitor MG132 in time- and dose-dependent manners, and the expression of PSD95 impaired Mas ubiquitination, indicating that the PSD95-Mas association inhibits Mas receptor degradation via the ubiquitin-proteasome proteolytic pathway. These findings reveal a novel mechanism of Mas receptor regulation by which its expression is modulated at the post-translational level by ubiquitination, and clarify the role of PSD95, which binds directly to Mas, blocking the ubiquitination and subsequent degradation of the receptor via the ubiquitin-proteasome proteolytic pathway.

Suppression effects of betaine-enriched spinach on hyperhomocysteinemia induced by guanidinoacetic acid and choline deficiency in rats.

Betaine is an important natural component of rich food sources, especially spinach. Rats were fed diets with betaine or spinach powder at the same level of betaine for 10 days to investigate the dose-dependent effects of spinach powder supplementation on hyperhomocysteinemia induced by guanidinoacetic acid (GAA) addition and choline deprivation. The GAA-induced hyperhomocysteinemia in rats fed 25% casein diet (25 C) was significantly suppressed by supplementation with betaine or spinach, and it was completely suppressed by taking 11.0% spinach supplementation. The choline deprivation-induced enhancement of plasma homocysteine concentration in rats fed 25% soybean protein diet (25S) was markedly suppressed by 3.82% spinach. Supplementation with betaine or spinach partially prevented the effects of GAA on hepatic concentrations of methionine metabolites. The decrease in activity of betaine-homocysteine S-methyltransferase (BHMT) and cystathionine ß-synthase (CBS) in GAA-induced hyperhomocysteinemia was recovered by supplementation with betaine or spinach. Supplementation with betaine or spinach did not affect BHMT activity, whereas it partially restored CBS activity in choline-deprived 25S. The results indicated that betaine or spinach could completely suppress the hyperhomocysteinemia induced by choline deficiency resulting from stimulating the homocysteine removal by both remethylation and cystathionine formation.

Dietary Serine and Sulfate-Containing Amino Acids Related to the Nutritional Status of Selenium in Lactating Chinese Women.

Previous studies suggested that serine can promote the synthesis of selenoproteins and the interaction, transformation, and replacement of serine, cysteine, and selenocysteine have been observed in the human body. This study was designed to clarify whether the dietary intakes of serine and sulfate-containing amino acids (SAAs) could directly affect the selenium (Se) nutritional status or the level of milk Se in lactating women. Breast milk and plasma samples were collected from a total of 264 lactating Chinese women when they revisited their local hospital at the 42nd day postpartum to detect the concentration of Se with ICP-MS and the content of selenoprotein P (SEPP1) and the activity of glutathione peroxidase 3 (GPX3) in the plasma by ELISA. The daily Se intake by each subject was calculated based on her own plasma Se concentration. The 24-h dietary record data for 3 consecutive days were collected to calculate their dietary intakes of protein together with each amino acid daily based on the China Food Composition Tables (CFCT). Ordinal polytomous logistic regression was applied to examine the determinants of BMI values for lactating women. For all subjects, the concentration of plasma SEPP1 and milk Se of participants with insufficient Se intake were significantly associated with the dietary intake of serine and 2 SAAs (methionine and cystine), respectively (P < 0.05). No significant correlation was found between each amino acid related to the synthesis of endogenous serine and every biomarker of the Se nutrition status in subjects with an insufficient dietary protein intake (P > 0.05). The ordinal logistic regression analysis showed that dietary protein intake (ordinal OR 1.012, 95% CI = 0.004-0.020, P = 0.002) and plasma SEPP1 (ordinal OR 0.988, 95% CI = - 0.023 to - 0.001, P = 0.036) affected the BMI value together in these lactating women. In conclusion, dietary serine and SAAs were found to directly affect the nutritional status, and both high protein intake and low plasma SEPP1 might be the health risks in these lactating Chinese women.

The PDZ domain protein CAL interacts with mGluR5a and modulates receptor expression.

In this study, we investigated the association of metabotropic glutamate receptor subtype-5a (mGluR5a) with cystic fibrosis transmembrane conductance regulator-associated ligand (CAL). Using glutathione-S-transferase pull-down techniques, we found that mGluR5a directly interacted with CAL, with the C-terminus of the receptor binding to the PSD95/Discslarge/ZO-1 homology domain of CAL. The last four amino acids (S-S-S-L) of the C-terminus of the receptor were essential determinants for the interaction. Co-immunoprecipitation experiments and immunofluorescence assays revealed that full-length mGluR5a also associated with intact CAL in vivo, an observation consistent with the results from studies on fragment interactions in vitro. Functionally, upon co-expression with mGluR5a, CAL profoundly inhibited the ubiquitination of mGluR5a and enhanced receptor expression at the protein level but not at the mRNA level. These findings reveal that mGluR5a protein expression is physiologically regulated via its interaction with CAL. These results also suggest a molecular mechanism by which mGluR5a protein expression may be regulated at the post-translational level by the CAL protein, possibly by blocking ubiquitination-dependent receptor degradation.

EBP50 exerts tumor suppressor activity by promoting cell apoptosis and retarding extracellular signal-regulated kinase activity.

The expression of Ezrin-radixin-moesin-binding phosphoprotein-50 (EBP50) and the intragenic mutation of the ebp50 gene have been reported to correlate with human breast cancer development, but the exact impacts on breast cancer development and its molecular mechanism are not fully understood. In this study, we investigate the potential function of EBP50 through over-expression in the breast cancer cell line, MDA-MB-231, which has low EBP50 protein expression levels. The effects of EBP50 over-expression on cellular proliferation, anchorage-independent growth and apoptosis were examined. In addition, the activity of extracellular signal-regulated kinase (ERK) was also determined. Our results show that a decrease of cellular proliferation and attenuation of colony-forming ability were evident in MDA-MB-231 cells stably transfected with an EBP50 expressing plasmid (EBP-231) when compared with control cells. There was also a statistically significant increase in spontaneous apoptosis in EBP-231 cells accompanied by an attenuation in ERK activity. Altogether, our results suggest that restoring EBP50 expression could suppress breast cancer cell proliferation by promoting cell apoptosis and inhibiting ERK activity, and that EBP50 may be a target for development of diagnostics and therapeutics in breast cancer.

Calculation of an Adequate Intake (AI) Value and Safe Range of Selenium (Se) for Chinese Infants 0-3 Months Old Based on Se Concentration in the Milk of Lactating Chinese Women with Optimal Se Intake.

The required selenium intake for optimal health in Chinese residents was published in 2014. However, the adequate intake (AI) value for Chinese infants 0-3 months old is not established. This study assessed the current selenium nutritional status of 264 lactating Chinese women from three geographical locations with different Se levels (Liangshan in Sichuan province, Enshi in Hubei province, and Xicheng District in Beijing), to screen mothers with optimal Se intake, and to modify the AI value of Se for Chinese infants 0-3 months old. Milk and plasma Se concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS) and glutathione peroxidase 3 (GPx3), and plasma selenoprotein P (SEPP1) was measured by ELISA. Daily Se intake (Y, µg/day) in lactating Chinese woman was calculated from plasma Se concentrations (X, µg/L) using the formula logY = 1.623 log(X) + 3.433. Plasma Se concentrations in lactating Chinese women were 78.19 ± 25.71, 112.48 ± 24.57, and 183.83 ± 45.81 µg/L from Se-deficient, Se-moderate, and seleniferous areas, respectively. Se intakes calculated from concentrations of plasma Se were 45.6 ± 21.69, 80.03 ± 27.69, and 223.10 ± 50.95 µg/day, respectively. An optimal dietary Se intake is not lower than the recommended nutrient intake (RNI) but not more than the tolerable upper intake level (UL). A range of 78-400 µg Se/day was defined as the optimal daily Se intake for lactating Chinese women. The percentages of mothers within this range in Sichuan, Beijing, and Enshi were 8.11, 45.13, and 6.06%, respectively. Based on milk Se concentrations of mothers with optimal daily Se intake, the adequate Se intake value and a safe range for Chinese infants 0-3 months of age were calculated as 15.29 and 8-35 µg Se/day, respectively. The Se status of Chinese lactating women has improved, particularly in traditionally Se-deficient and Se-toxic regions. A safe range for daily Se intake in Chinese infants may be regarded as a guideline for infant formula.