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Lei Y.,Zhejiang University | Li X.,Tongde Hospital of Zhejiang Province | Akash M.S.H.,Zhejiang University | Akash M.S.H.,Government College University at Faisalabad | And 5 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2015

Salbutamol (SAL) is known as quick-acting β-2 receptor agonist and its use in humans for pulmonary diseases and/or in animal feed is limited because of associated potential hazardous effects on health. Several techniques are available for the detection of SAL, but are expensive and time consuming. Here for the first time, a novel pre-assembled DNA immunoprobe-based immuno-PCR assay was developed to investigate the levels of SAL in human urine samples and compared the proposed immuno-PCR assay for the detection of SAL with that of direct competitive ELISA. Under the optimized conditions, the assay showed a linear range over seven orders of magnitude, whereas the limit of detection of SAL in buffer was found to be 21. fg/mL. Current immuno-PCR assay exhibited a 300-fold better detection limit for SAL as compared to one achieved with direct competitive ELISA using the same antibody. In conclusion, it has been found that the developed method is highly sensitive and simple method that can significantly enhance the detection sensitivity for small molecules. Moreover it can be modified and used for detecting other small molecules and/or chemicals that exist in the environment and are responsible for the environmental pollution. © 2014 Elsevier B.V.

Lei Y.,Zhejiang University | Fang L.,Zhejiang University | Akash M.S.H.,Zhejiang University | Akash M.S.H.,Government College University at Faisalabad | And 4 more authors.
Journal of Food Science | Year: 2013

Aflatoxin M1 (AFM1) is a main cause of hepatocarcenogenoma in Chinese population. Measurement of aflatoxin exposure in human may help in providing clear evidence for the exposure of specific environmental pollutants in certain population. "One child policy" in China offered parents more careful to choose safe food during pregnancy, but no reports published on the efficacy of their endeavor. In present study, we aimed to assess the exposure of AFM1 in Chinese pregnant women. The urine samples were collected from 600 volunteers from Zhejiang province, China and the urinary concentration of AFM1 was measured using ELISA kit. AFM1 was detected in 84% of the pregnant women. The geometric mean and 95th percentile concentration of AFM1 in pregnant women were 50.3 ng/L and 633.5 ng/L, respectively. Our results point out that pregnant women especially are at the high risk of exposure to AFM1. Our results also indicate that although "one child policy" offered parents to pay more attention for the selection of safe food, but detection of AFM1 in urine of pregnant women indicate that more foods containing AFM1 still need to be detected. Highest exposure of AFM1 in pregnant women indicates that awareness campaigns must be started especially in the rural areas of China regarding the possible hazardous effects of AFM1 exposure in pregnant women. © 2013 Institute of Food Technologists®.

Lei Y.,Zhejiang University | Zhang Q.,Zhejiang University | Fang L.,Zhejiang University | Akash M.S.H.,Zhejiang University | And 5 more authors.
Drug Testing and Analysis | Year: 2014

We simultaneously set up two competitive (direct and indirect) enzyme-linked immunosorbent assays (ELISAs) based on the same antibody for estimation of cotinine (COT) in pregnant women especially and population generally exposed to environmental tobacco smoke. The results show that the limits of detection (LODs) for direct competitive ELISA and indirect competitive ELISA were 0.04 μgL-1 and 0.1 μgL-1, respectively. Direct competitive ELISA was found to be more sensitive than indirect competitive ELISA. Thereafter, we applied our direct competitive ELISA for the detection of COT from urinary samples taken from 450 volunteers from the Zhejiang Province of China. COT was detected in 100% of participants with concentration ranging from LOD to 5358.0 μgL-1. The GM and 95th percentile concentration of COT in pregnant women were 6.3 μgL-1 and 57.2 μgL-1, respectively. Males had statistically higher COT concentrations than females (P<0.0001), active smokers had statistically higher COT concentrations than non-smokers (P<0.0001), whereas, non-pregnant women were found to have higher COT concentration than pregnant women. We conclude that our developed direct competitive ELISA is useful for detecting the COT in urinary concentration of human. The human urinary data obtained in this study indicated that common people generally and pregnant women especially were highly exposed to COT. Further studies are needed to focus on the sources of exposure, potential health effects and risk assessment of exposure to COT. © 2014 John Wiley & Sons, Ltd.

Zhou L.,Zhejiang University | Lei Y.,Hangzhou EPIE Bio detection Technology Ltd | Zhang D.,Zhejiang University | Ahmed S.,Zhejiang University | Chen S.,Zhejiang University
Science of the Total Environment | Year: 2016

Dibutyl phthalate (DBP) has been extensively used as a plasticizer in many daily products, which is highly toxic to human, notably affecting the reproductive and developmental function. As the previous method is expensive, time-consuming, low sensitivity and just focused on the environment. Present study was aimed to establish an ultra-sensitive and simple method based on good quality monoclonal antibody, applying to evaluate excretion level of DBP in urine samples of Chinese population directly. A monoclonal antibody was generated and characterized after fusion of myeloma cells with spleen cells isolated from BALB/c mouse. The mouse was previously immunized using a specially designed amino derivative of DBP conjugated with bovine serum albumin (BSA) as immunogen. Cross-reactivity values of the monoclonal antibody against DBP, di-isobutyl phthalate (DIBP) were observed 100% and 1.25%, while for dimethyl phthalate (DMP), butyl benzyl phthalate (BBP) and didecyl phthalate (DDP) the values were <0.06%. The standard curve was constructed at 0-50ngmL-1 and good linearity (R2=0.994) was achieved. The observed IC50 (7.34ngmL-1) and LOD (0.06ngmL-1) values was improved 1000-fold to polyclonal antibody and 5-fold to other monoclonal antibodies. A total 1246 urine samples were analyzed and the detection frequency of DBP was observed 72.87% by ic-ELISA. The 95th percentile and mean concentration of DBP were 12.07 and 3.00ngmL-1. Acceptable recovery rates of DBP were 97.8-114.3% and coefficients variation 5.93-11.09%. The concentrations of DBP in females were found significantly higher (p<0.05) than males. Similarly, the DBP in middle aged and low educated individuals was found higher (p<0.001) than the others. Considering the adverse health effects, DBP internal exposure in the Chinese population should be reduced. The ic-ELISA method has been proved as a cost effective, specific, and highly sensitive screening tool to detect DBP in urinary samples. © 2015 Elsevier B.V.

Lei Y.,Zhejiang University | Fang L.,Zhejiang University | Hamid Akash M.S.,Zhejiang University | Liu Z.,Hangzhou EPIE Bio detection Technology Ltd | And 2 more authors.
Analytical Methods | Year: 2013

Bisphenol A (BPA) is widely used to manufacture polycarbonate plastics and epoxy resins, which are in widespread use in China. Concerns about potential health impacts from exposure to BPA among the general population are increasing day by day. A sensitive and specific antibody was prepared to develop and compare direct and indirect competitive enzyme-linked immunosorbent assays (ELISAs) for the determination of BPA in human urine. The IC50 value and limit of detection (LOD) for the direct competitive ELISA were 5.5 ng mL-1 and 0.03 ng mL-1 respectively whereas, for the indirect competitive ELISA, the IC50 value and LOD were 7.0 ng mL-1and 0.08 ng mL-1, respectively. We found that the direct competitive ELISA was more specific and sensitive than the indirect competitive ELISA. The established immunoassays were also applied in the determination of BPA in human urine samples. The results from fortified samples and real samples indicated that the direct competitive ELISA was more sensitive and reliable for the measurement of BPA in human urine as compared to the indirect competitive ELISA. © 2013 The Royal Society of Chemistry.

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