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Microparticle Enzyme Immunoassay (microparticle + enzyme_immunoassay)
Selected AbstractsThe effects of acetylsalicylic acid on proliferation, apoptosis, and invasion of cyclooxygenase-2 negative colon cancer cellsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 11 2002H.-G. Yu Summary Background Acetylsalicylic acid (ASA, aspirin), the most common nonsteroidal anti-inflammatory drug (NSAID), has been shown to have a protective effect against the incidence and mortality of colorectal cancer. However, the mechanism of its anticancer function remains unclear. The aim of this study was to determine the effects of acetylsalicylic acid on proliferation, apoptosis, and invasion in human cyclooxygenase-2 (COX-2) negative colorectal cancer cell lines. Materials and Methods After treatment with various concentrations of ASA, cell proliferation was measured in the human colon cancer cell line SW480. Apoptotic cells were identified by transmission electron microscopy, acridine orange staining, and flow cytometry. The invasive potential of SW480 cells was detected using an in vitro invasion assay. The production of carcinoembryonic antigen was measured by microparticle enzyme immunoassay. Expression of Bcl2, Bax, CD44v6, and nm23 were evaluated by immunocytochemistry. Results ASA significantly inhibited the proliferation of SW480 cells and stimulated apoptosis. Production of carcinoembryonic antigen and the invasive potential of SW480 cells were also inhibited by ASA. After treatment with ASA, down-regulation of Bcl2 and CD44v6 expression and up-regulation of nm23 expression were observed in SW480 cells. No obvious effect of ASA was found on Bax expression. Conclusion Our findings reveal that ASA inhibits the proliferation and promotes apoptosis in the human colon cancer cell line SW480. Down-regulation of Bcl2 expression might represent a potential mechanism by which ASA induces apoptosis in this COX-2 negative colon cancer cell line. Our results also suggest that ASA decreases the invasive potential of these colon cancer cells. Decreased CEA content and CD44v6 expression and elevated nm23 expression may contribute to the effect of ASA on invasive potential of SW480 colon cancer cells. [source] Intrafamilial transmission of hepatitis C in Egypt,HEPATOLOGY, Issue 3 2005Mostafa K. Mohamed The incidence of hepatitis C (HCV) infection and associated risk factors were prospectively assessed in a cohort of 6,734 Egyptians from 2 rural villages who were negative for antibodies to HCV (anti-HCV). Initial and follow-up sera were tested for anti-HCV by enzyme immunoassay (EIA), and possible incident cases were confirmed by using the microparticle enzyme immunoassay (MEIA) and tested for HCV RNA. All follow-up serum samples converting from negative to positive without detectable HCV-RNA were further tested by recombinant immunoblot assay. Over an average of 1.6 years, asymptomatic anti-HCV seroconversion occurred in 33 people (3.1/1,000 person-years [PY]), including 28 (6.8/1,000 PY) in the Nile Delta village (AES), where prevalence was 24% and 5 (0.8/1,000 PY) in the Upper Egypt village (baseline prevalence of 9%). The strongest predictor of incident HCV was having an anti-HCV,positive family member. Among those that did, incidence was 5.8/1,000 PY, compared (P < .001) with 1.0/1,000 PY; 27 of 33 incident cases had an anti-HCV,positive family member. Parenteral exposures increased the risk of HCV but were not statistically significant; 67% of seroconverters were younger than 20 years of age, and the highest incidence rate (14.1/1,000 PY) was in children younger than 10 who were living in AES households with an anti-HCV,positive parent. In conclusion, young children would especially benefit from measures reducing exposures or preventing infection with HCV. (HEPATOLOGY 2005.) [source] Switching from HPLC/UV to MEIA for whole blood sirolimus quantitation: comparison of methodsJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 6 2006Luigi Alberto Pini Abstract Sirolimus is a immunosuppressive agent for renal transplant recipients. Monitoring of whole blood sirolimus concentration is necessary in order to improve clinical outcomes. An increasing number of clinical laboratories (4,14% during 2005) are using microparticle enzyme immunoassay (MEIA) for sirolimus quantitation but previous reports indicated a high variability, with a mean difference of 17% for MEIA method vs. high-performance liquid chromatography/ultraviolet (HPLC/UV). This study was aimed at comparing the reliability of MEIA with the HPLC/UV method. Blood samples from transplant patients were processed using both HPLC/UV and MEIA assays. Comparison and Bland-Altman plots, as well as regression analysis and paired t -test were used to compare results of the assays. Concentrations were stratified into three groups and used to investigate whether any observed difference between methods could be influenced by sirolimus concentration. Regression analysis yielded a coefficient of correlation R of 0.9756, the line of best fit being y=0.9832x+0.1976. The statistical analysis showed no difference between the two sets of experimental data. The average percentage difference between the two methods was found to be ,0.2±19.2%. On the basis of our present results, the tested MEIA assay is able to quantify sirolimus concentration with a clinically acceptable imprecision, similar to that of HPLC/UV method. J. Clin. Lab. Anal. 20:239,244, 2006. © 2006 Wiley-Liss, Inc. [source] Detection of hepatitis C virus RNA in paraffin-embedded tissues from patients with non-Hodgkin's lymphomaAMERICAN JOURNAL OF HEMATOLOGY, Issue 3 2004Semra Paydas Abstract The aim of this study is to detect the possible role of hepatitis C Virus (HCV) in lymphomagenesis. HCV-RNA and anti-HCV antibodies were studied in tissue and serum samples taken from patients with non-Hodgkin's Lymphoma (NHL). The prevalence of HCV, the clinical presentation of these cases, and association with histologic subtypes were determined. RT-PCR was used to detect the HCV-RNA in serum and tissue samples. The anti-HCV antibodies were tested with microparticle enzyme immunoassay. Immunohistochemistry with the ABC method was used to detect the HCV core protein in HCV-RNA+ cases. RNA could be detected in 30 of 35 cases, and other tests were performed in these 30 samples. HCV-RNA was detected in 11 tissue samples (11/30, 37%). HCV core protein was studied in 10 of 11 HCV-RNA+ cases, and 1,3% nuclear staining was found in only 2 samples. Serologically, HCV-RNA was detected in 7 of 30 samples (23.3%) and anti-HCV antibody was detected in 3 of 30 samples (10%). Detection of HCV-RNA in 37% of the lymphoma tissue samples suggests that HCV may have a role or is a contributing factor in the pathogenesis of lymphoma. The very low HCV core protein in lymphoma tissues may be due to the low viral load in lymphoid tissues and/or higher sensitivity of the PCR method. Detection of anti-HCV antibody in only three cases may be associated with undetectable levels of antibodies due to the immune deficiency in cases with NHL. Am. J. Hematol. 76:252,257, 2004. © 2004 Wiley-Liss, Inc. [source] Serum inhibin B and follicle-stimulating hormone levels as markers in the evaluation of azoospermic men: a comparisonANDROLOGIA, Issue 5 2005A. Halder Summary Inhibin B is a glycoprotein hormone produced mainly by Sertoli cells of the testes in the adult male. It selectively suppresses the secretion of pituitary follicle-stimulating hormone (FSH) and has local paracrine actions in the testes. Its measurement is useful for investigating the role of inhibin B in male gonadal dysfunction. The objective of this study was to investigate the efficacy of serum inhibin B in men with nonobstructive azoospermia in comparison with FSH. Serum concentration of FSH was measured using microparticle enzyme immunoassay, inhibin B by specific solid phase sandwich enzyme-linked immunosorbent assay in men with nonobstructive azoospermia (n = 46) and control fertile men (n = 5). Mean inhibin B and FSH level was 104.6 pg ml,1 and 4.0 mIU ml,1 in control men whereas the value for nonobstructive azoospermic men was 17.06 pg ml,1 and 31.1 mIU ml,1 respectively. Inhibin B and FSH levels were significantly different in azoospermia than controls (P < 0.0001). There were six cases of nonobstructive azoospermia with normal inhibin B. Testicular histology did not find any evidence of spermatogenesis in three cases with normal inhibin B. This demonstrated that inhibin B was not a superior predictor for testicular function in our study. [source] Influence of rabeprazole and lansoprazole on the pharmacokinetics of tacrolimus in relation to CYP2C19, CYP3A5 and MDR1 polymorphisms in renal transplant recipientsBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 4 2007Masatomo Miura Abstract The objective of this study was to evaluate whether genetic polymorphisms of CYP2C19, CYP3A5 and MDR1 significantly impact the interaction between tacrolimus and rabeprazole or lansoprazole. Seventy-three recipients were randomly assigned after renal transplantation to receive repeated doses of tacrolimus for 28 days with a regimen of either 20 mg of rabeprazole or 30 mg of lansoprazole. Blood concentrations of tacrolimus were measured by microparticle enzyme immunoassay. The mean daily dose and the dose-adjusted area under the plasma concentration-time curves from 0 to 12 h (AUC0,12) of tacrolimus coadministered with rabeprazole or lansoprazole were the lowest and highest, respectively, in CYP2C19 poor metabolizers (PMs) having the CYP3A5*3/*3 genotype (0.084 and 0.112 mg/kg/day and 1.269 and 1.033 ng·h/ml/mg/kg, respectively). On the other hand, the mean dose-adjusted AUC0,12 of tacrolimus coadministered with rabeprazole or lansoprazole were the highest in CYP2C19 PMs having the MDR13435CC+CT genotype, but not significantly. The present study indicates that there are significant interactions between tacrolimus and rabeprazole or lansoprazole in CYP2C19 PM renal transplant recipients bearing the CYP3A5*3/*3 genotypes. For recipients having these genetic polymorphisms, lower dosages of tacrolimus are required to achieve the target therapeutic index. Copyright © 2007 John Wiley & Sons, Ltd. [source] A limited sampling strategy for tacrolimus in renal transplant patientsBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 4 2008Binu S. Mathew WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT , Tacrolimus trough concentration is being currently used for dose individualization. , Limited sampling strategies (LSS) have been developed and validated for renal transplant patients. , Earlier literature has suggested that measurement of tacrolimus AUC is more reliable than trough with respect to both rejection and nephrotoxicity. WHAT THIS STUDY ADDS , Four thousand renal transplants take place annually in India, with many patients prescribed tacrolimus in combination with mycophenolate and steroid. , In this study a LSS with two points, i.e. trough and 1.5 h postdose was developed and validated to estimate AUC0,12. , The added benefit of only a single additional sample with completion of blood collection in 1.5 h and minimum additional cost makes this a viable LSS algorithm in renal transplant patients. , In patients having tacrolimus trough concentrations outside the recommended range (<3 and >10 ng ml,1 in the treatment protocol in our institution) or having side-effects in spite of trough concentrations in the desired range, we can estimate AUC using this LSS for a better prediction of exposure. AIMS To develop and validate limited sampling strategy (LSS) equations to estimate area under the curve (AUC0,12) in renal transplant patients. METHODS Twenty-nine renal transplant patients (3,6 months post transplant) who were at steady state with respect to tacrolimus kinetics were included in this study. The blood samples starting with the predose (trough) and collected at fixed time points for 12 h were analysed by microparticle enzyme immunoassay. Linear regression analysis estimated the correlations of tacrolimus concentrations at different sampling time points with the total measured AUC0,12. By applying multiple stepwise linear regression analysis, LSS equations with acceptable correlation coefficients (R2), bias and precision were identified. The predictive performance of these models was validated by the jackknife technique. RESULTS Three models were identified, all with R2 , 0.907. Two point models included one with trough (C0) and 1.5 h postdose (C1.5), another with trough and 4 h postdose. Increasing the number of sampling time points to more than two increased R2 marginally (0.951 to 0.990). After jackknife validation, the two sampling time point (trough and 1.5 h postdose) model accurately predicted AUC0,12. Regression coefficient R2 = 0.951, intraclass correlation = 0.976, bias [95% confidence interval (CI)] 0.53% (,2.63, 3.69) and precision (95% CI) 6.35% (4.36, 8.35). CONCLUSION The two-point LSS equation [AUC0,12 = 19.16 + (6.75.C0) + (3.33.C1.5)] can be used as a predictable and accurate measure of AUC0,12 in stable renal transplant patients prescribed prednisolone and mycophenolate. [source] A serological and molecular survey of hepatitis B in children 15 years after inception of the national hepatitis B vaccination program in eastern China,JOURNAL OF MEDICAL VIROLOGY, Issue 9 2009Ying Dong Abstract The emergence of mutations in the hepatitis B virus (HBV) S gene has threatened the long-term success of vaccination programs since the worldwide introduction of effective vaccines against hepatitis B. This study was conducted on 5,407 children (0,8 years old) in eastern China in 2007. We analyzed the prevalence of HBsAg, anti-HBs, and "a"-determinant mutations in the HBV S gene by microparticle enzyme immunoassays, PCR, and DNASTAR software. The total HBsAg prevalence was 1.52% (82/5,407) in the children and increased with age. In contrast, the positive rate (65.42%, 2,374/3,629) and the titers of anti-HBs decreased with age. The predominant infection was HBV of genotype C and serotype adr (45/51; 88% of cases). Mutations of I126T, amino acid 137 (nt553T deletion mutation), G145A, G145R, and F158S were found in the children; the mutations of amino acid 137 and F158S have not been reported previously. The total prevalence of mutant strains was 14% (7/51). To investigate whether the infection resulted from maternal transmission, we compared the S gene sequences in 16 mother,child pairs. Fourteen mother,child pairs exhibited the same HBV genotype, with 99.5,100% sequence homology in the S gene, while two pairs exhibited different genotypes. This study suggested that the hepatitis B vaccination strategies in eastern China have been successful. Although the emergence of "a"-determinant mutations in the HBV S gene have resulted in HBV infection in immunized children, this does not pose a threat to the vaccination strategies. The HBV-infected children had contracted the infection via vertical transmission. J. Med. Virol. 81:1517,1524, 2009. © 2009 Wiley-Liss, Inc. [source] | ||||||||||