1.Study on the determination method of chromium picolinate in health food
Dajin YANG ; Congrong FANG ; Zhutian WANG
Chinese Journal of Food Hygiene 2001;13(3):8-10
For developing the determination method of chromium picolinate in health food by HPLC,extraction method and HPLC operation conditions such as columns,mobile phase had been optimized.Long term stability test of chromium picolinate had been done.Recovery of the standard spiked >93%,the RSD was 3.1,the lowest detection limit was 10.0 mg/kg,the result fits the demand of the analysis of health food.This method can be used in analysis of the content of chromium picolinate in types of tablet and capsule health food.2 years store experiment in room temperature showed that chromium picolinate was stable.
2.Determination of perchlorate in food by ultra performance liquid chromatography-tandem mass spectrometry
Weiwei HE ; Jie YANG ; Yuxin WANG ; Yuzhe LI ; Dawei CHEN ; Yunfeng ZHAO ; Shuang ZHOU ; Congrong FANG
Chinese Journal of Food Hygiene 2017;29(4):438-444
Objective To establish a method for the determination of perchlorate in food by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).Methods The perchlorate residue in spices and condiments was extracted with water,that in vegetables and fruits was extracted with acetonitrile-water (1∶ 1,V/V),and that in meat,poultry,eggs,milk and aquatic products was extracted with acetonitrile-water (2∶ 1,V/V).The supernatant was cleaned up with C18 SPE (3 ml,200 mg),and the detection was carried out by UPLC-MS/MS with internal standardmethod for quantification.Results The calibration curve was linear in the concentration range of 0.3-20.0 pg/L (R2 ≥0.999),the recovery was in the range of 82.6%-108.6%,the relative standard deviation (RSD) was in the range of 1.0%-9.9%,and the limit of detection was 2.0 μg/kg for milk,and 10.0 μg/kg for other food.Conclusion The method was simple,accurate and highly sensitive,and suitable for the determination of perchlorate in food.
3.Exploration of the effect and regulatory mechanism of hepatitis B virus on the expression of apolipoprotein B
Chengliang ZHU ; Yan LI ; Chuanhua ZHAN ; Shiyong HAO ; Pingan ZHANG ; Congrong LI ; Fang LIU
Chinese Journal of Microbiology and Immunology 2011;31(1):30-33
Objective To explore the effect of hepatitis B virus(HBV) on the expression of apolipoprotein B(ApoB) and its regulatory mechanism. Methods mRNA and protein expression of ApoB in HepG2 and HepG2.2.15 cells was measured by RT-PCR and Western blot, serum ApoB levels in patients with HBV infection and in healthy individuals were measured by biochemical analyzer Olympus 5400, the expression of ApoB difference among healthy individuals, patients with chronic hepatitis B, liver cirrhosis, and hepatocellular carcinoma were analyzed, HBV infectious clone pHBV1.3 was tranfected into HepG2 cells,and expression of ApoB and microsomal triglyceride transfer protein(MTP) was measured by RT-PCR and Western blot. Results Expression of ApoB mRNA and protein was lower in HepG2.2.15 cells than in HepG2 cells, serum apoB levels was much lower in patients with chronic hepatitis B and liver cirrhosis as compared to healthy individuals( P <0.05 ), HBV could inhibit the expression of ApoB and MTP at mRNA and protein levels. Conclusion HBV may downregulate the synthesis and secretion of ApoB via inhibits the expression of MTP.
4.Enrichment of circulating fetal nucleated red blood cell for non-invasive prenatal diagnosis with a new polyclonal antibody specific to fetal hemoglobin
Dongling TANG ; Xin ZHOU ; Yan LI ; Fang ZHENG ; Congrong LI ; Yuan RONG
Chinese Journal of Laboratory Medicine 2008;31(11):1235-1239
Objective To investigate the feasibility of a new polyclonal antibody specific to fetal hemoglobin (HbF) and its application in enrichment of circulating fetal nucleated red blood cell(NRBC) for non-invasive prenatal diagnosis. Methods A polyclonal antibody against a synthetic peptide comprising residues 69-78 of the γ-chain of HbF was prepared and conjugated to carrier protein KLH as the immunogen according to the specific antigenic determinant. The peptide-KLH solution was mixed with freund's complete or incomplete adjuvant and immunized goat to prepare specific polyclonal antibody against the γ-chain of fetal hemoglobin. After purification with protein G, maternal blood was obtained from 32 pregnant women at 22 to 39 weeks of gestation. NRBCs were separated and then stained with antibody against the γ chain of HbF. All the positive cells were collected by micromanipulator under microscopic observation, and whole genome was amplified by improved primer extension preamplification (PEP). Multiplex polymerase chain reaction amplification at nine different polymorphic short tandem repeat (STR) loci was also used to determine origin of the positive cells isolated from maternal blood. Results NRBCs stained with antibody against the γ chain of HbF were found in all of the blood from the 32 cases. Attached positive cells with anti-HbF staining have unique morphological characteristics, low nucleus-to-cytoplasm ratio, brown cytoplasm and blue dense nucleus after hematoxylin counterstain under microscopic observation, which can distinguished NRBCs with other cells. A total of 183 NRBCs were found in all of 32 pregnant women at a range of 0.6~1.8 cell/ml venous blood. The accurate rate was 90.6% by the STR genotype identification. Conclusion The antibodies specific to fetal γ-chain of fetal hemoglobin with synthetic peptide technology may have wide clinical utility in identification of fetal NRBCs from maternal circulation for non-invasive prenatal genetic diagnosis.
5.Investigation on association of activating transcription factor 6 Ala145Pro variant with glucose and lipid metabolism in Chinese
Cheng HU ; Wei-Ping JIA ; Hui WAN ; Rong ZHANG ; Congrong WANG ; Xiaojing MA ; Qichen FANG ; Kunsan XIANG ;
Chinese Journal of Endocrinology and Metabolism 1986;0(04):-
Objective To investigate the association of activating transcription factor 6(ATF6)gene Ala145Pro(GCG→CCG)variant with glucose and lipid metabolism in Chinese.Methods The genotypes were determined by PCR-RFLP in 689 Chinese in Shanghai.Among them,361 subjects showed normal glucose regulation,250 cases were newly-diagnosed diabetic patients without taking any drug and 78 cases were probands of early-onset type 2 diabetes pedigrees.The following phenotypes were measured:body height and weight to calculate BMI;waist,hip and femoral circumference to calculate waist-to-hip ratio and waist-to-femoral ratio;blood pressure;plasma glucose levels obtained at 0 and 120 minute during 75 g oral glucose tolerance test;fasting serum lipid profile including total cholesterol,triglyceride,high density lipoprotein-cholesterol and low density lipoprotein-cholesterol;body fat percentage and distribution.Results(1)The frequency of C allele is significantly lower in probands from early-onset type 2 diabetes patients compared with subjects with normal glucose regulation(P=0.035).(2)In subjects with normal glucose regulation,the CC+CG genotype had a significantly lower level of high density lipoprotein cholesterol as compared with GG genotype(P=0.014).(3)In type 2 diabetic patients,the CC+CG genotype had a significantly higher level of low density lipoprotein-cholesterol as compared with GG genotype(P=0.041).Conclusion These findings suggest that variant of ATF6 plays a role in glucose and lipid metabolism in Chinese.