133 research outputs found
Glycated hemoglobin measurements from dried blood spots: Reliability and relation to results obtained from whole blood samples
Background: Main objective was to measure glycated hemoglobin (HbA1c) in dried blood spots on paper filter and in whole blood samples in diabetic patients to evaluate relationship between two methods and their respective reliability. Methods: The 20�10 μl of venous blood samples of 33 diabetics were blotted onto the filter paper allowed to dry at room temperature and then stored at 25°C and 4°C. HbA1c was measured via the Turbidimetric Inhibition Immunoassay Technique. The relation was evaluated with correlation and linear regression tests using STATA software and SPSS. Agreement between the results obtained from the dried blood spots and others was evaluated using the Bland and Altman. The pitman's permutation test was also employed to compare the difference in variance. Results: A high positive correlation was detected between whole blood samples and dried blood spots stored at 4°C (r2 =0.90) and at 25°C (r2 = 0.95). The Bland and Altman graphs, as well as the Pitman tests, showed statistically significant differences in variability between the values obtained from whole blood samples and those derived from dried spots stored at 4°C (p=0.05) or 25°C (p=0.004). Conclusion: HbA1c measurements from dried blood spots on the filter paper yielded reliable results. That the Hitachi autoanalyzer is available in most countries renders this assay less costly than the High Performance Liquid Chromatography Method (HPLC). In addition, the filter paper method for Immuno-turbidimetric estimations of HbA1c at different temperatures is reliable and may be particularly useful in outpatient diabetes clinic
Investigating the relationship between client importance and audit quality: Evidence from TSE
The purpose of this study is to investigate the effect of client importance on audit quality in Tehran Stock Exchange (TSE). The results of previous researches in some countries suggest that the auditor independence may be affected by the economic importance of certain clients, which can affect audit quality. The results of this study, using a sample comprising of 1164 year-company observations during 2005 to 2012 from among listed companies in TSE and using logistic regression analysis showed that there is no significant relationship between the client importance and qualified audit opinion (as a measure of audit quality). In other words, it can be said that the independence and audit quality in Iran's capital market is not affected by the economic importance of clients. The results after controlling other factors that based on the previous researches can affect the qualified audit opinion showed that the probability of revealing qualified audit report has a positive relationship with financial leverage and performance of the previous year and has a negative relationship with the concentration of ownership, the size of the auditor, returns on assets and liquidity ratios
Investigating the relationship between client importance and audit quality: Evidence from TSE
The purpose of this study is to investigate the effect of client importance on audit quality in Tehran Stock Exchange (TSE). The results of previous researches in some countries suggest that the auditor independence may be affected by the economic importance of certain clients, which can affect audit quality. The results of this study, using a sample comprising of 1164 year-company observations during 2005 to 2012 from among listed companies in TSE and using logistic regression analysis showed that there is no significant relationship between the client importance and qualified audit opinion (as a measure of audit quality). In other words, it can be said that the independence and audit quality in Iran's capital market is not affected by the economic importance of clients. The results after controlling other factors that based on the previous researches can affect the qualified audit opinion showed that the probability of revealing qualified audit report has a positive relationship with financial leverage and performance of the previous year and has a negative relationship with the concentration of ownership, the size of the auditor, returns on assets and liquidity ratios
Design of an expression system for rapid production of tri-functional antibody substitution of hybrid hybridoma technology
Tri-functional antibodies, as an effective novel tumor targeting agents, are composed of anti-CD3 rat IgG2b and an anti-tumor antigen antibody. We have intended to develop a novel drug system to induce the apoptosis of HER2-expressing tumor cells, activate and engage cytotoxic T lymphocytes, natural killer cells, and macrophages. In addition, the drug can inhibit programmed death ligand 1 (PDL-1)-expressing tumor cells. We have designed a mammalian vector system suitable to express the trifunctional antibody composed of antiHER2�human-CD80: human-IgG1Fc antibody. This antibody contains four chains of anti-HER2/CL, anti-HER2/CH1-3, B7.1/CL, and B7.1/CH1-3 within the human IgG1 framework and so the vector system will simultaneously express the four chains. The amino acid/nucleotide sequences datasets were retrieved from the GenBank, UniProtKB and PDB databases. The heavy and light chains variable domain framework regions and complementarity determining regions of scA21 antibody were determined by IMGT/V-QUEST and Paratome software. The amino acid sequences of tri-functional antibody chains manually were assembled and converted to DNA sequences by sequence manipulation suite software. The adapting codon usage of these DNA sequences was performed by JCAT software. Finally, the secondary structures of obtained RNAs from the DNAs were individually analyzed by RNAfold program. The Prodigy equilibrium dissociation constant, a ratio of koff/kon, between the antibody and its antigen for hantiHER2VHCH-HER2, hantiHER2VLCL-HER2, CD80CH-CD28, and CD80CL-CD28 were equal to 3.60E-10, 3.10E-9, 1.10E-8 and 2.70E-10; respectively. These findings were confirmed the composition and nano-molar affinity of the respective constructs. A single specific no-cloning expression vector, pHuchiTriomAb, was designed in silico with a desirable length of 8.292 Kbps and bidirectional expression potential for the four chimeric antibody chains. This construct was designed, and gene codon usage adapted to be expressed within CHO cells and secreted a trifunctional antibody into the cell culture medium by interleukin 21 signal peptide.This robust expression system for rapid production of tri-functional antibody has been designed to substitute hybrid hybridoma technology (quadroma and trioma)with the facilitated purification of the trifunctional antibody from the antibody variants. © 2018 Tehran University of Medical Sciences. All rights reserved
Investigating the Relationship between Procalcitonin Serum Level and Response to Treatment in Urosepsis Patients
Background and Aim: Urinary tract infection is a common and painful disease in humans. Rapid and timely diagnosis of sepsis and its differentiation from non-infectious causes that manifest with similar symptoms is very important because timely antibiotic treatment onset in patients with sepsis is very vital in reducing mortality and improving the final outcome of patients. This study was performed aiming to investigate the relationship between procalcitonin serum level changes and response to treatment in patients in 2016. Materials and Methods: In this study 15 women and 15 men of the patients over 18 years of age who were admitted to Yasouj Shahid Beheshti Hospital were selected. Then, urine culture and blood sample were taken simultaneously from the patients on day 5 and day 10 and two weeks after the start of treatment, and in case of negative urine culture in each one of the cultures, the procalcitonin serum level was measured. To analyze the data SPSS software was used. Findings: The mean and standard deviation of procalcitonin serum level before and after treatment were 8.88 ± 1.24 and 0.05 ± 0.01, respectively (p = 0.001). The mean and standard deviation of procalcitonin serum level before and after treatment in patients with complicated and uncomplicated urinary tract infection were 10.97 ± 1.46 and 0.54 ± 0.08, respectively (p = 0.001). Conclusion: Procalcitonin biomarker can be used in patients with urinary tract infection to evaluate the response to treatment and the duration of admission in the hospital and the duration of antibiotic therapy
The urgent need to develop novel strategies for the diagnosis and treatment of snakebites
Snakebite envenoming (SBE) is a priority neglected tropical disease, which kills over one hundred thousand people per year. However, many millions of survivors also suffer through disabilities and long-term health consequences. The only treatment, antivenom, has a number of major associated problems, not least, adverse reactions and limited availability. This emphasises the necessity for urgent improvements to the management of this disease. Administration of antivenom is too frequently based on symptomatology, which results in wasting crucial time. The majority of SBE-affected regions rely on broad-spectrum polyvalent antivenoms that have a low content of case-specific efficacious immunoglobulins. Research into small molecular therapeutics such as varespladib/methyl-varespladib (PLA2 inhibitors) and batimastat/marimastat (metalloprotease inhibitors) suggest that such adjunctive treatments could be hugely beneficial to victims. Progress into toxin-specific monoclonal antibodies as well as alternative binding scaffolds such as aptamers hold much promise for future treatment strategies. SBE is not implicit during snakebite, due to venom metering. Thus, the delay between bite and symptom presentation is critical and when symptoms appear it may often already be too late. The development of reliable diagnostical tools could therefore initiate a paradigm shift in the treatment of SBE. While the complete eradication of SBE is an impossibility, mitigation is in the pipeline, and new treatments are emerging
Immunohistochemical discrimination of wild-type EGFR from EGFRvIII in fixed tumour specimens using anti-EGFR mAbs ICR9 and ICR10
Background:The human epidermal growth factor receptor (EGFR) is an important therapeutic target in oncology, and three different types of EGFR inhibitors have been approved for the treatment of cancer patients. However, there has been no clear association between the expression levels of EGFR protein in the tumours determined by the FDA-approved EGFR PharmDx kit (Dako) or other standard anti-EGFR antibodies and the response to the EGFR inhibitors.Method:In this study, we investigated the potential of our anti-EGFR monoclonal antibodies (mAbs; ICR9, ICR10, ICR16) for immunohistochemical diagnosis of wild-type EGFR and/or the type-III deletion mutant form of EGFR (EGFRvIII) in formalin-fixed, paraffin-embedded human tumour specimens.Results:We found that the anti-EGFR mAb in the EGFR PharmDx kit stained both wild-type and EGFRvIII-expressing cells in formalin-fixed, paraffin-embedded sections. This pattern of EGFR immunostaining was also found with our anti-EGFR mAb ICR16. In contrast, mAbs ICR10 and ICR9 were specific for the wild-type EGFR.Conclusion:We conclude that mAbs ICR9 and ICR10 are ideal tools for investigating the expression patterns of wild-type EGFR protein in tumour specimens using immunohistochemistry, and to determine their prognostic significance, as well as predictive value for response to therapy with EGFR antibodies.British Journal of Cancer advance online publication, 7 February 2012; doi:10.1038/bjc.2012.27 www.bjcancer.com
Single domain antibodies: promising experimental and therapeutic tools in infection and immunity
Antibodies are important tools for experimental research and medical applications. Most antibodies are composed of two heavy and two light chains. Both chains contribute to the antigen-binding site which is usually flat or concave. In addition to these conventional antibodies, llamas, other camelids, and sharks also produce antibodies composed only of heavy chains. The antigen-binding site of these unusual heavy chain antibodies (hcAbs) is formed only by a single domain, designated VHH in camelid hcAbs and VNAR in shark hcAbs. VHH and VNAR are easily produced as recombinant proteins, designated single domain antibodies (sdAbs) or nanobodies. The CDR3 region of these sdAbs possesses the extraordinary capacity to form long fingerlike extensions that can extend into cavities on antigens, e.g., the active site crevice of enzymes. Other advantageous features of nanobodies include their small size, high solubility, thermal stability, refolding capacity, and good tissue penetration in vivo. Here we review the results of several recent proof-of-principle studies that open the exciting perspective of using sdAbs for modulating immune functions and for targeting toxins and microbes
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