[Investigation on the recommended dose of prebiotic in health food in China in 1996-2022].

OBJECTIVE: To understand the recommended dose distribution of prebiotic-containing health food in China. METHODS: The overall recommended dose of prebiotic health food was available from the label information of approved prebiotic health food from 1996 to 2022; the recommended dose distribution of prebiotic-containing health food was analyzed from different healthy functions and different ways of addition. RESULTS: There were 174 prebiotic-containing health food products with clear dose information, respectively, involving 5 prebiotics including Fructooligosaccharides, Galactooligosaccharides, Isomaltooligosaccharides, Xylo-oligosaccharides and Polydextrose, and the majority of prebiotics were added in combination, with 159 products. The recommended dose range of prebiotic-containing health food products was wide, and in general, the dose of prebiotic-containing health food products used alone was higher than the dose used in combination. The recommended daily intake range of health food containing Fructooligosaccharides was 5.28-17 500 mg/d, the recommended daily intake range of health food containing Isomaltooligosaccharides was 220-28 000 mg/d, the dose range of health food containing Xylo-oligosaccharides was 8.4-2 800 mg/d, the dose range of health food containing Polydextrose was 4-12 120 mg/d, the number of Galacto-Oligosaccharides products Only two kinds of products were included, with doses of 259.8 mg/d and 3500 mg/d, respectively. The claimed functions of prebiotic health food products were focused on laxative function, immunity enhancement, and regulation of intestinal flora. The application dose of prebiotic health food with different functional compounding additions was close to the overall dose. CONCLUSION: The recommended dosage range of prebiotics in health food containing prebiotics in China is large, and prebiotics in products are mainly added by compounding.

[Effect of high selenium on insulin signaling pathway PI3K-AKT-mTOR in L02 cells].

OBJECTIVE: To observe the effect of high selenium on insulin signaling pathway PI3K-AKT-mTOR in L02 cells. METHODS: One group of L02 cell was treated with different concentrations of selenomethionine(SeMet, 0.001, 0.0025, 0.005, 0.0075, 0.01, 0.025, 0.05, 0.075 and 0.1µmol/L) for 48 h, then cultured with serum-free medium for 4 h and stimulated with 1 µmol/L insulin for 15 min. The insulin signaling pathway(PI3K-AKT-mTOR) was detected by WB. Another group of L02 cell was treated with the same concentrations of SeMet as above for 48 h. The cell supernatant and lysates were collected for the analysis of SELENOP and GPX1, respectively by WB. RESULTS: The expressions of P-AKT-(Ser-473), P-AKT-(Thr-308), PI3K and mTOR in L02 cells under high-Se were decreased with the increase of SeMet concentration. The expressions of GPX1 and SELENOP were enhanced with the increase of SeMet. CONCLUSION: The insulin signaling pathway, PI3K-AKT-mTOR, was damaged in L02 cell under high-Se stress.

Impacts of ovarian preservation on the prognosis of neuroendocrine cervical carcinoma: a retrospective analysis based on machine learning.

BACKGROUND: Neuroendocrine cervical carcinoma (NECC) is a rare but aggressive malignancy with younger patients compared to other common histology types. This study aimed to evaluate the impacts of ovarian preservation (OP) on the prognosis of NECC through machine learning. METHODS: Between 2013 and 2021, 116 NECC patients with a median age of 46 years received OP or bilateral salpingo-oophorectomy (BSO) and were enrolled in a retrospective analysis with a median follow-up of 41 months. The prognosis was estimated using Kaplan-Meier analysis. Random forest, LASSO, stepwise, and optimum subset prognostic models were constructed in training cohort (randomly selected 70 patients) and tested in 46 patients through receiver operator curves. Risk factors for ovarian metastasis were identified through univariate and multivariate regression analyses. All data processing was carried out in R 4.2.0 software. RESULTS: Among 116 patients, 30 (25.9%) received OP and showed no significantly different OS compared with BSO group (p = 0.072) and got better DFS (p = 0.038). After construction of machine learning models, the safety of OP was validated in lower prognostic risk group (p > 0.05). In patients ≤ 46 years, no impacts of OP were shown for DFS (p = 0.58) or OS (p = 0.67), and OP had no impact on DFS in different relapse risk population (p > 0.05). In BSO group, regression analyses showed that later stage, para-aortic LNM, and parametrial involvement were associated with ovarian metastasis (p < 0.05). CONCLUSIONS: Preserving ovaries had no significant impact on prognosis in patients with NECC. OP should be considered cautiously in patients with ovarian metastasis risk factors.

[Comparative study on the essential composition content of commercial infant formula with the requirements in the new national food safety standard in China from 2017 to 2022].

OBJECTIVE: In order to understand the distribution of the essential nutrients content in commercial infant formula in China, and to compare its conformity with the new national standard(GB 10765-2021). METHODS: A total of 477 infant fomulas with production data from January 2017 to June 2022 were collected in China. Information in the product labels was recorded and the distribution of nutrient contents was analyzed, compare with the national food safety standard. RESULTS: Compared with GB 10765-2010, the new standard had 12 essential nutrients content revised, and 10 of which had lower limit values adjusted and 5 of which had upper limit values adjusted. Both the lower and upper limits were increased for three items, including vitamin D, choline and selenium. Compared with the newly revised 12 essential nutrients in the national food safety standard, the coincidence rate of 3 items was 100%, and the coincidence rate of 3 items was more than 80%. The coincidence rate of the actual content of essential nutrients in some products was low, the reason was that they did not meet the lower limit requirements of the new national standard, for example, the non-coincidence rate of vitamin D was as high as 99.79%. In addition, the national food safety standard adjusts choline from an selectable nutrient to an essential one, and the proportion of choline added to commercial products was 84.7%. CONCLUSION: The change of the content of essential nutrients in the new standard has little influence on the products sold in our country. There are a few essential nutrient in the products on the market that need to be adjusted to raise the nutrient level.

[Comparative study on the essential composition content of commercial follow-up formula for young children with the requirements in the new national food safety standard in China from 2017 to 2022].

OBJECTIVE: To understand the distribution of the essential composition content of commercial follow-up formula for young children in China, to analyze the differences with the new requirements of national food safety standard, and to promote the implementation of the new national standard(GB 10767-2021). METHODS: The label information on the total of 483 follow-up formula for young children permitted from January 2017 to June 2022 were collected and recorded, the distribution of essential compositions were analyzed and compared with the new national food safety standard. RESULTS: Compared with GB 10767-2010, 23 essential compositions were revised in the new national standard, 2 new essential compositions, α-linolenic acid and carbohydrates, were required, and 8 minimum requirements and 4 maximum requirements were revised, 16 new maximum requirements were developed. The whole change of the new standard was major. Comparing with GB 10767-2021, there were 8 essential compositions in commercial products with 100% compliance rate and 9 with more than 95% compliance rate, the discordance rate of pantothenic acid, folic acid, vitamin C and Vitamin D was more than 20%, Vitamin D has the highest discordance rate 97.10%. CONCLUSION: Although the revision of the essential composition requirements in the new national standard is major, the compliance rate of almost essential compositions is high. A few of individual essential compositions in some commercial products cannot meet the new standards requirements, the main reason is those can not reach the increased new minimum requirements, especially on vitamin D.

[Investigation on the addition of dietary fiber in infant and follow-up formula in China from 2017 to 2022].

OBJECTIVE: To investigate the addition of dietary fiber in infant formula approved in recent 5 years. METHODS: A total of 1438 infant formula milk powder approved in China from January 2017 to June 2022 were collected and the addition rate, content and mixture of dietary fiber components such as galactooligosaccharide(FOS), fructooligosaccharide(GOS), polyfructose, polyglucose, raffinose and yeast ß-dextran were statistically analyzed. RESULTS: Among the 1438 infant formulas, 84.07%(1209) were added with dietary fiber, and the addition rate increased yearly. Among them, the addition rate of GOS(79.82%) and FOS(79.74%) was the highest, and the median amount of dietary fiber components was 3.00 g/100 g. Among the products added with various dietary fiber components, there were 762 products added with GOS and FOS, The addition ratios of GOS and FOS were mainly concentrated at 1∶1. CONCLUSION: The addition rate of dietary fiber in infant formula milk powder in China is constantly increasing, however there are large differences in the addition amount, dietary fiber combination and proportion of different products.

[Comparative study on the essential composition content of commercial follow-up formula for older infant with the requirements in the new national food safety standard in China from 2017 to 2022].

OBJECTIVE: To understand the distribution of the content range of essential ingredients in commercial follow-up formula for older infants in China, analyze the differences between the content of essential ingredients in commercial older infant formula milk powder in China and the requirements of the new national standard(GB 10766-2021). METHODS: The label information of 478 commercial follow-up formula for older infant registered and approved from January 2017 to June 2022 were collected and entered. The distribution of essential ingredients was statistically analyzed, which was compared with the requirements of the new national food safety standard. RESULTS: The new national standard has 31 essential components. Compared with the old national standard(GB 10767-2010), five indicators of carbohydrate, α-linolenic acid, choline, selenium and manganese were added. The new national standard has 28 essential component requirements revised, including 13 adjusted the lower limit, 7 adjusted the upper limit, and 16 essential components added the upper limit. Among the approved 478 older infant formula milk powders, the distribution of 11 essential ingredients were all in line with the new national standard, and 14 essential ingredients were less than the lower limit of the new national standard. The essential ingredients whose minimum value was less than the lower limit of the new national standard and the proportion exceeds 50% were vitamin D, iodine and choline. with the proportions(number of cases) of 98.33%(470 cases), 74.06%(354 cases) and 72.37%(275 cases), respectively. The maximum value of essential ingredients exceeded the maximum requirements stipulated in the new national standard, and the protein in 13.18%(63 cases) of the older infant formula milk powder was higher than the maximum requirements of the new national standard. CONCLUSION: The content of essential components in most commercial products in China meets the new national standard requirements. Some essential ingredients need to be adjusted.

[Investigation on the addition of microbial food cultures in infant and follow-up formula in China from 2017 to 2022].

OBJECTIVE: To understand the addition of microbial food cultures in infant and follow-up formula milk powder in China. METHODS: The product information of infant and follow-up formula milk powder approved in China from 2017 to 2022 was investigated, including the query platform and packaging label information, and the strains, addition rates and addition amount of microbial food cultures were statistically analyzed. RESULTS: From 2017 to 2022, a total of 1438 infant and follow-up formula milk powder products were approved in China, of which 434 products were added with microbial food cultures, 6 types of strains were used, namely Bifidobacterium animalis Bb-12, Bifidobacterium lactis HN019, Bifidobacterium lactis Bi-07, Lactobacillus fermentum CECT5716, Lactobacillus rhamnosus HN001 and Lactobacillus acidophilus NCFM, the top three addition rates were Bifidobacterium animalis Bb-12, Bifidobacterium lactis HN019 and Bifidobacterium lactis Bi-07, the addition rate were 79.72%, 18.43% and 12.67%, respectively. The addition amount of the strains ranged from 1×10~6 to 6×10~7 CFU/g, the median value was 1×10~6 CFU/g. CONCLUSION: There is insufficient scientific evidence on the feeding effect, types and amounts of microbial food cultures added to infant and follow-up formula in China.

[Study of high selenium interfering with glucose and one-carbon metabolism in hepatocytes in vitro].

OBJECTIVE: To investigate the effects of high selenium environment on the expression of selenoproteins and enzymes related to glucose and one-carbon metabolism in normal human hepatocytes. METHODS: Ten different concentrations of selenomethionine(SeMet, 0, 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 5 and 10 µmol/L) was added into the normal human hepatocyts and incubated for 48 hours. The expressions of selenoprotein(GPX1 and SELENOP1) and metabolic enzymes(PHGDH, SHMT1, MTHFR and MS) were analyzed by Western blot. RESULTS: When the concentration of SeMet was 0-10 µmol/L, the expression trend of selenoprotein(GPX1 and SELENOP1) is similar, which first increases and then decreases. There is a slight difference between the inflection points of GPX1 and SELENOP1, which are respectively 0.5 µmol/L and 0.1 µmol/L. The expression trend of serine de novo synthesis pathway key enzymes(PHGDH) and folate cycle metabolizing enzymes(SHMT1, MTHFR and MS) is similar to that of selenoproteins, which also increases first and then decreases, but the inflection points are different, which are respectively 0.1 µmol/L(PHGDH and SHMT1) and 0.01 µmol/L(MTHFR and MS). CONCLUSION: Under the high selenium environment, the glycolytic bypass-serine de novo synthesis pathway is activated to synthesize endogenous serine due to the insufficient intracellular serine supply, causing abnormal glucose metabolism, which is an important extension to the hypothesis of the molecular mechanism of high selenium causing IR.

[Intervention study to inhibit the glucose metabolic remodeling in hepatocytes induced by high-selenium in vitro].

OBJECTIVE: To observe the effect of exogenous serine or glycine on the synthesis of selenoprotein and endogenous serine and the expression of metabolic enzymes in hepatocytes cultured with high-selenium in vitro and its dose-response relationship. METHODS: The experiment was divided into two parts, namely a inhibition experiment and a dose-response experiment, using L02 cells as the intervention target. In the inhibition experiment, the blank control group, high-Se(SeMet) group, serine intervention group and high-Se+serine intervention group were set up. Both SeMet and serine were given at a level of 0.05 µmol/L, and the blank control group was given the same volumes of saline. In the dose-response experiment, the concentration of SeMet was 0.05 µmol/L, and the intervention concentration gradients of serine or glycine were 0, 0.05, 0.1, 0.5, 1, 5, 10, 50, 100 and 500 µmol/L. The expression of phosphoglycerate dehydrogenase(PHGDH)、serine hydroxymethyltransferase 1(SHMT1)、methylenetetrahydrofolate reductase(MTHFR)、selenoprotein P(SELENOP) and glutathione peroxidase 1(GPX1)was detected by Western Blot(WB). RESULTS: (1)In the inhibition experiment, compared with the blank control group, the expression of selenium proteins(GPX1 and SELENOP) in L02 cells of the other three groups were significantly increased(P<0.05). Compared with the high expression of PHGDH in L02 cells of high-Se group, the expressions of PHGDH, SHMT1 and MTHFR in high-Se + serine group were significantly decreased(P<0.05). (2) In the dose-response experiment, the expression of PHGDH enzyme in L02 cells gradually decreased with the increase of the concentration of exogenous serine or glycine, showing an obvious dose-dependent effect. In contrast, none of the other metabolic enzymes(SHMT1 and MTHFR) showed similar trends in protein expression. CONCLUSION: The upregulated expression of PHGDH, the key enzyme in the de novo synthesis pathway of serine in hepatocytes cultured with high-selenium can be inhibited feedback by exogenous serine or endogenous serine transformed from exogenous glycine directly.

[Distribution of vitamin K_2 content in Chinese traditional fermented soybean products].

OBJECTIVE: To determine the content of vitamin K_2 in different types of fermented bean products and analyze the difference of vitamin K_(2 )content. METHODS: A total of 98 kinds of typical fermented bean products were included in Chinese traditional fermented bean products(Douchi, Sufu, soybean paste). Process, region, sales volume, raw materials and flavor were considered, and the content of vitamin K_2 in fermented bean products was determined by high performance liquid chromatography. RESULTS: Chinese bean fermented foods generally contained vitamin K_2, and the subtype menaquinone-7(MK-7)was the main one. The content of vitamin K_2 in Douchi was the highest(437.55 µg/100 g), the content of vitamin K_2 in Sufu and Soybean paste were lower(7.48 µg/100 g and 2.47 µg/100 g). The content of vitamin K_2 in bacterial Douchi was higher than that in Mucor type and Aspergillus oryzae type which were 403.94, 232.98 and 81.00 µg/100 g(P<0.05). Soybean type Douchi was higher than that in black bean type of Douchi which were 610.41, 178.08 µg/100 g(P<0.05), and the content of vitamin K_2 in dry Douchi was higher than the content of vitamin K_2 in water Douchi which were 1 517.45 µg/100 g, 297.58 µg/100 g(P<0.05). However, there were no significant difference in the content of vitamin K_2 in Soybean paste and Sufu in different types and regions(P > 0.05). CONCLUSION: Vitamin K_2 is widely contained in Chinese fermented bean products, and its content is mainly affected by fermentation microorganisms and processing technology.

[Staple food habits on glycemic response: a controlled feeding trial].

OBJECTIVE: To study the effects of staple food on the glycemic responses through a controlled feeding trial. METHODS: In November 2020, two groups of volunteers with different staple food habits(the rice group, n=35, and the wheat group, n=35), were recruited from Changzhi Medical College in Shanxi Province. They were subjected to a two-stage feeding trial, in which their staple food habits were maintained in the first stage(staple food fortification period, 4 weeks) and then swapped in the second stage(staple food swap period, 4 weeks), while keeping the rest of the dietary components same. A continuous glucose monitoring system was used to monitor the glycemic response of glucose, steamed buns and steamed rice, equivalent to 50 g of available carbohydrate(CHO). Blood glucose level up to 120 minutes postprandial, incremental area under the curve(iAUC) and glycemic index(GI) were analyzed. RESULTS: During the staple food fortification period, the glycemic response to steamed buns at 15 min(5.43±0.69 vs.5.14±0.50 mmol/L, P=0.047), 30 min(6.63±0.98 vs.6.10±0.70 mmol/L, P=0.012), 45 min(6.81±1.15 vs.6.21±0.67 mmol/L, P=0.011) and 60 min postprandial(6.03±0.96 vs.5.56±0.59 mmol/L, P=0.017) in the rice group were higher than the wheat group, and the trends for blood glucose fluctuation during the 120 minutes after consuming steamed buns were different between the two groups. During the staple food swap period, the 120 min iAUC(83.24±30.15 vs.69.32±26.25 mmol·min/L, P=0.032) and GI(88±24 vs.75±33, P=0.041) of the rice group to steamed buns were higher than the wheat group. Comparing the differences between the two groups in the staple food exchange period and the staple food intensification period, the rice group had an increased glycemic response to steamed buns(P=0.007), while the wheat group had an increased glycemic response to glucose(P<0.001), steamed buns(P<0.001) and steamed rice(P=0.018). The 120 min iAUC of steamed buns in the rice group increased(83.24±30.15 vs.70.12±26.02 mmol·min/L, P=0.029), and the 120 min iAUC of rice in the wheat group(69.75±32.32 vs.54.87±20.43 mmol·min/L, P=0.040) increased. CONCLUSION: Even to the same food, there are significant differences in the glycemic responses of people with different staple food habits, and short-term changes in the intake of staple food will lead to differences in the glycemic response.

[Effects of rice wheat intervention on intestinal microflora of rats based on metagenomics].

OBJECTIVE: To investigate the effects of rice on intestinal microflora in rats. METHODS: Thirty 4-week-old male SD rats were randomly divided into control group, rice group and wheat group according to body weight. The control group was fed with AIN-93 diet, the rice group and the wheat group was fed with the AIN-93 diet which the carbohydrate was replaced with rice and wheat, respectively, for 4 weeks. At the end of the experiment, lipid related biochemical indexes were determined, and the contents of the distal colon(feces) of rats were collected for macro factor detection. RESULTS: From the beginning to the end of feeding, there was no difference in weight gain among the groups. After the end of the experiment, there was no difference among lipid-related indicators and blood glucose. α diversity showed that there was no difference in the diversity of intestinal microbiota between the rice and wheat groups, and the gene abundance analysis of intestinal microbiota in the wheat group showed that the gene abundance of intestinal microbiota was lower. The difference analysis of intestinal microbiota result showed that compared with the rice group, the wheat group was composed of higher proportion of verrucomicrophyla and lower proportion of Bacteroidetes. Lefse analysis showed that the surface group was enriched with Akkermansia Muciniphila, Bifidobacterium animalis, and a variety of beneficial bacteria such as Faecalibaculum rodentium and Intestinimonas butyriciproducens, while Prevotella copri was rich in the rice group. Glycoside hydrolases 8, glycoside hydrolases 16, glycoside hydrolases 99 and glycosyl transferase family 56. CONCLUSION: Rice or wheat as different carbohydrate sources have different effects on the composition of intestinal microflora and carbohydrate-related active enzymes in rats.

[Effects of brown rice on metabolomics related to glucose and lipid in normal rats].

OBJECTIVE: To investigate the effects of whole grain rice on blood sugar, blood lipid and metabonomics compared with ordinary feed and refined rice. METHODS: According to the initial body weight and fasting blood glucose, 36 male SD rats were randomly divided into 3 groups: control group, RG-rice group and WG-rice group, fed with AIN-93 G feed, feeds prepared with refined rice flour or brown rice flour, respectively, for 18 weeks. Food intake and body weight were monitored weekly. At the end of the experiment, abdominal aortic blood was taken to measure blood glucose and blood lipids, and untargeted metabolomics was performed. RESULTS: During the experiment, the body weight growth and food intake of rats in each group were basically the same. Fasting blood glucose(FBG) in RG-rice group were(10.12±1.51)mmol/L, which were significantly higher than those in other groups, hepatic glycogen in RG-rice group were(0.90±0.33)mg/g, which were significantly higher than those in WG-rice group. TC and LDL in RG-rice group were(1.85±0.21)mmol/L and(0.84±0.10)mmol/L, respectively, which were significantly lower than those in control group and RG-rice group(P& lt; 0.05). The non-targeted metabolomics result were compared in pairs. A total of 30 metabolic differences were found between the control and RG-rice groups, involving 8 potential pathways, 12 metabolic differences were found between the control and WG-rice groups, involving 2 potential pathways, 18 metabolic differences were found between the RG-rice and WG-rice groups, involving 4 potential pathways. Pathway enrichment was performed again according to the correlation analysis of differential metabolites with blood glucose and blood lipids. The result showed that the FBG-related pathways include glycerophospholipid metabolism and glutathione metabolism. TG-related pathways include glycine, serine and threonine metabolism, ether lipid metabolism, glycerophospholipid metabolism, and glyoxylic acid and dicarboxylic acid metabolism. TC-related pathways include D-glutamine and D-glutamate metabolism, glycine, serine and threonine metabolism, alanine, aspartic acid and glutamate metabolism, arginine biosynthesis, glycerophospholipid metabolism, glutathione metabolism, and glyoxylic acid and dicarboxylic acid metabolism. LDL-related pathway include glycerophospholipid metabolism. CONCLUSION: Eating more refined rice may increase blood sugar, brown rice helps to maintain a relatively low blood lipid level. Glycerol phospholipid metabolism is a common pathway that rice affects blood glucose and blood lipid metabolism in normal rats.

[Effects of intervention of sodium alginate on intakes of foods and macronutrients and situation of serum amino acids in healthy male youths].

OBJECTIVE: To research the effect of sodium alginate intervention on the nutritional intake of healthy young men. METHODS: Recruited 20 healthy university students as research subjects. The experiment was divided into two periods: the dietary balance period and the sodium alginate intervening period, and each period was expected to be 28 days. During the dietary balance period, all meals in every day of experiment are provided by the research team; during the sodium alginate intervening period, based on the diet during the balanced diet period, sodium alginate was added to the staple food steamed buns(10 g sodium alginate per person per day). The experiment compares the food intake types, main nutrient intake levels and serum amino acid changes of subjects before and after intervention. RESULTS: Adding sodium alginate can significantly reduce the intake of energy(-242.4 kcal), protein(-11 g)and carbohydrates(-47.3 g, P<0.05)in healthy subjects, but there was no significant effect on the intake of fat(-2.9 g, P=0.496)and cholesterol(-14.9 mg, P=0.070), and because of the addition of alginate, the whole dietary fibers obtained a significant increase(+7.8 g, P<0.05). After the intervention of sodium alginate, there was no significant change in the intake of rice, soy products, poultry products and vegetable oil, while the intake of wheat products(-49.6 g), egg foods(-2.6 g), dark-colored vegetables(-29.1 g), light-colored vegetables(-63.8 g)and fruits(-37 g)decreased significantly(P<0.05). Most of the essential amino acids in the subjects' serum increased significantly after the intervention, especially the valine in serum rise from 226.9 µmol/L to 466.4 µmol/L(P<0.05). CONCLUSION: Sodium alginate can play a dietary fiber-like effect, produce satiety, reduce nutrient intake of subjects, especially carbohydrates, so sodium alginate has the potential to limit energy intake and control postprandial blood sugar. And sodium alginate also has a potential positive effect on the metabolism of amino acids in healthy people, especially the metabolism of essential amino acids.

[Effects of different varieties and processing degree grains on blood glucose and blood lipid in rats].

OBJECTIVE: To investigate the effects of whole grains(WG) and refined grains(RG) on blood glucose, blood lipid and inflammatory factors in normal rats, and the common effects of different whole grains. METHODS: 2×2 factorial experiments were designed according to grain sources(rice & wheat) and processing precision(whole grain & refined grain). According to the initial body weight and fasting blood glucose, 48 male SD rats were randomly divided into four groups: RG rice group, WG rice group, RG wheat group and WG wheat group. They were fed with 45% refined rice, whole grain rice, refined wheat and whole grain wheat respectively for 18 weeks. The formula was in accordance with AIN-93 G. Food intake and body weight were monitored weekly. Fasting blood glucose, lipid, inflammatory factors and organ pathology were detected at the end of the experiment. RESULTS: During the experiment, the body weight growth and food intake of rats in each group were basically the same. At the end of the experiment, fatty liver appeared in varying degrees, while the kidney of rats in RG rice group and RG wheat group showed epithelial steatosis. Biochemical indexes showed that blood urea nitrogen(UN), fasting blood glucose(FBG), total cholesterol(TC), triglyceride(TG), low density lipoprotein(LDL)and monocyte chemoattractant protein-1(MCP-1)in RG wheat group were significantly higher than those in WG wheat group(P<0. 05), while high density lipoprotein(HDL)level in RG wheat group was significantly lower than that in WG wheat group(P<0. 05), and there was no significant difference in other indexes. The result of factorial analysis showed that the differences of FBG, serum insulin, homeostasis model assessment of insulin resistance(HOMA-IR)and C-reactive protein(CRP)caused by different grain processing degree were significant, but there was no significant difference between rice and wheat varieties(P>0. 05). CONCLUSION: Studies have shown that long-term feeding of refined grains can lead to fasting blood glucose, blood lipid abnormality and renal pathological changes in rats, and proper feeding of whole grains can delay the development of adverse symptoms.

[Relationship between rs2282679 gene locus polymorphism and vitamin D deficiency in college students].

OBJECTIVE: To investigate the relationship between vitamin D binding protein gene rs2282679 A/C polymorphism with blood vitamin D levels. METHODS: A total of 286 eligible subjects were selected from one university in Hebei Province. Serum 25-hydroxylated vitamin D levels were measured by liquid chromatography-mass spectrometry, and gene chip was used for genotyping of rs2282679 locus. Statistical analysis was performed using R software. RESULTS: A total of 285 participants in the study completed the experiment, and result indicated that the distribution of the rs2282679 locus A/C polymorphism in the participants was consistent with the Hardy-Weinberg equilibrium. The genotype of rs2282679 was significantly associated with serum vitamin D insufficiency and deficiency(P=0. 031). Allele A was a risk factor for vitamin D insufficiency and deficiency. The OR value of allele C relative to A was 0. 65, and the genetic pattern of allele C relative to A was dominant(P=0. 03). CONCLUSION: The vitamin D-binding protein gene rs2282679 was significantly associated with serum vitamin D insufficiency and deficiency in college students, and A-allele is a risk factor accounting for vitamin D insufficiency and deficiency in college students.

[Effects of methionine on the activity of cystathionine-ß-synthase].

OBJECTIVE: To investigate the effects of methionine on the activity of cystathionine-ß-synthase. METHODS: A total of 56 male rats of the Wistar were randomly divided into 7 groups: 10% casein(10 C) group, 40% casein(40 C) group, 10 C+0.75% L-methionine(10 CM) group, 10 C+amino acid mixture(10 CAA) group, 10 CAA-methionine(10 CAA-Met) group, 10 C+ essential amino acid(10 C+EAA) group, and 10 C+ non-essential amino acid(10 C+NEAA) group, with 8 rats in each group for 10 days. RESULTS: The plasma homocysteine concentration significantly increased from(17.1±0.3)µmol/L to(50.7±4.8)µmol/L and(40.5±3.9)µmol/L in rats fed 10 CM and 10 C+EAA diets(P<0.01). Supplementation with methionine induced hyperhomocysteinemia. Compared to 10 C, the activity of hepatic cystathionine-ß-synthase(CBS) were significantly increased in the experimental group except for 10 CM(P<0.05). The activity of hepatic CBS was the largest increases in diets with 40 C and the smallest increases in 10 C+NEAA. The activity of hepatic betaine-homocysteine S-methyltransferase(BHMT) were increased in the experimental group except for 10 CAA-Met and 10 C+NEAA(P<0.05). CONCLUSION: The increased CBS activity induced by high protein diets is determined by high amino acid intake rather than methionine supplemention.

[Determination of 3-hydroxyisovaleryl carnitine in plasma and urinary excretion by ultra-performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS ) method was developed for the determination of 3-hydroxyisovaleryl carnitine in plasma and urinary excretion. METHODS: Plasma and urinary excretion samples were centrifugated with high speed at 3000 x g for 10 minutes, and the MCX solid phase extraction column was used to filter and purify the liquid samples. The following procedures were elution, wash-out, redissolve, detection. The chromatographic separation was achieved on a Waters Acquity UPLC BEH C18 column (2.1 mm x 50 mm, 1.7 microm), with a mobile phase composed of 0.1% formic acid in water-methanol with gradient elution. Analyte quantification was performed in the positive electrospray ionization mode and multiple monitoring. The quantification and qualification were performed using the internal standard of 3-hydroxyisovaleryl carnitine, then the evaluation for accuracy and precision were followed. RESULTS: The linear range of 3-hydroxyisovaleryl carnitine were 0.1-20.0 microg/L in the plasma and 5.0-200 microg/L in urine, with both the linear correlation coefficient above 0. 99. Moreover, in three standard levels, rate of recovery in plasma and urine ranged from 78.6% to 115.6%. The RSD of six parallel determination for the 3HIA-carnitine in plasma and urine were 4.80% and 5.70% respectively. The detection and quantification limits for plasma and urine were 0.04 microg/L, 0.1 microg/L and 0.03 microg/L, 0.08 microg/L, respectively. CONCLUSION: The sample preparation method is simple and fast, and the method can be used to analyze 3-hydroxyisovaleryl carnitine in plasma and urinary excretion efficiently and sensitively.

[Effects of biotin on blood glucose regulation in type 2 diabetes rat model].

OBJECTIVE: To explore the effect of biotin on blood glucose regulation in rats and its possible mechanism. METHODS: According to initial body weight and blood glucose, we randomly divided the 90 Wistar rats into 5 groups: the normal control group, model group, biotin low-dose group (0. 6mg/kg BW), biotin medium-dose group (3. 0 mg/kg BW) and biotin high-dose group (6. 0 mg/kg BW). After 2 months, the rats with HFS feed were injected with STZ (25 mg/kg BW) to manufacture diabetic rat model. After the OGTT experiment at 10th week, the blood glucose, insulin, liver/muscle glycogen and other biochemical indexes were detected. The GCK, PCK1 mRNA expression were measured with RT-PCR method. RESULTS: Biotin has a certain improvement on postprandial glucose in diabetic rats. Compared with the model group, the AUC and the 30min postprandial blood glucose of biotin high-dose group were significantly decreased (P <0. 05). Biotin can affect some key enzyme gene in glucose metabolism, such as GCK, PCK1. CONCLUSION: The possible mechanism of the decreasing biotin blood sugar in diabetic rats may by promoting the synthesis of glycogenand reducing gluconeogenesis.