Avicenna Journal of Medical Biotechnology
Year:2015 | Volume:7 | Issue:4 (27)|Papers Count:8

Evidence Based Medicine (EBM) can be found as far back as the 1940s. However, it was in 1972 that the concept first came into play, originated by Professor Archie Cochrane, in his book, Effectiveness & Efficiency: Random Reflections on Health Services. This was the foundation for evidence based research, and in 1992 a facility was funded by the UK government, with the aim of performing randomly controlled tests on health services.This is no coincidence since evidence-based medicine suggests a personal responsibility for clinicians to keep abreast of research that would be difficult without the information access that the web provides. Evidence-based medicine is now generally perceived to be the dominant operating system in conventional medicine. The term “evidence-based medicine” first appears in 1991, in a piece by Gordon Guyatt.

Metastatic colorectal cancer is the fourth most common cause of death due to cancer after those of lung, stomach, and liver. Anti epidermal growth factor receptor drugs as a targeting therapy seem to be good candidates for curing metastatic colorectal cancer. Two available anti epidermal growth factor receptor monoclonal antibodies are cetuximab and panitumumab which have been approved for metastatic colorectal cancer treatment. Through the available literature on NCBI and clinical trials, 31 clinical trials in which cetuximab or panitumumab as monotherapy or in combination with chemotherapy were used for the treatment of metastatic colorectal cancer patients in different line settings and 12 clinical trials in which bevacizumab was used for being compared with anti epidermal growth factor receptor monoclonal antibodies or chemotherapy were chosen for reviewing and comparing the results of overall survival, progression free survival and adverse effects. Cetuximab and panitumumab are well accepted for the treatment of mCRC patients at all stages in different line settings. Although cetuximab administration in metastatic colorectal cancer patients is mostly associated with better overall survival and panitumumab results in better progression free survival, to confirm the superiority of each of them in the treatment protocol of epidermal growth factor receptor monoclonal antibodies, more clinical trials with larger sample size are needed. Through current available data from clinical studies, it can be concluded that the best treatment outcome is achieved by a combination of anti epidermal growth factor receptor monoclonal antibodies with conventional chemotherapy.

Background: Antibodies have a wide application in diagnosis and treatment. In order to maintain optimal stability of various functional parts of antibodies such as antigen binding sites, several approaches have been suggested. Using additives such as poly-saccharides and polyols is one of the main methods in protecting antibodies against aggregation or degradation in the formulation. The aim of this study was to evaluate the protective effect of various additives on the specific reactivity of monoclonal antibodies (mAbs) against recombinant HBsAg (rHBsAg) epitopes.Methods: To estimate the protective effect of different additives on the stability of an-tibody against conformational epitopes (S3 antibody) and Linear linear epitopes (S7 and S11 antibodies) of rHBsAg, heat shock in at 37oC was performed in liquid and solid phases. Environmental factors were considered to be constant. The specific reactivity of antibodies was evaluated using an ELISA method. The data were analyzed using SPSS software by Mann-Whitney nonparametric test with the confidence interval of 95%.Results: Our results showed that 0.25 M sucrose, 0.04 M trehalose and 0.5% BSA had the most protective effect on maintaining the reactivity of mAbs (S3) against conformational epitopes of rHBsAg. Results obtained from S7 and S11 mAbs against linear characteristics showed minor differences. The most efficient protective additives were 0.04 M trehalose and 1 M sucrose.Conclusion: Nowadays, application of appropriate additives is more interested important for increasing the stability of antibodies. It was concluded that sucrose, trehalose and BSA have considerable effects on the specific reactivity of anti rHBsAg mAbs during long storage.

Background: Anti-cancer potential of marine natural products such as polysaccharides represented therapeutic potential in oncological researches. In this study, we extracted total polysaccharide from brittle star [Ophiocoma erinaceus (O. erinaceus)] was extracted and investigated the chemopreventive efficacy of Persian Gulf brittle star polysaccharide was investigated in HeLa human cervical cancer cells.Methods: To extract polysaccharide, dried brittle stars were grinded ground and ex-tracted mechanically. Then, detection of polysaccharide was performed by phenol sulfuric acid, Ultra Violet (UV)-sulfuric acid method and FTIR. The anti proliferative activity of isolated polysaccharide was examined by MTT assay and evaluation of cell death induced was done through morphological cell changes; Propodium Iodide staining, fluorescence microscopy and caspase-3, -9 enzymatic measurements. To assess its un-derlying mechanism, expression of Bax, Bcl-2 was evaluated.Results: The polysaccharide detection methods demonstrated isolation of crude poly-saccharide from Persian Gulf brittle star. The results revealed that O. erinaceus poly-saccharide suppressed the proliferation of HeLa cells in a dose and time dependent manner. Morphological observation of DAPI and Acridine Orange/Propodium Iodide staining was documented by typical characteristics of apoptosis apoptotic cell death. Flow cytometry analyses exhibited the accumulation of treated cells in sub-G1 region. Additionally, polysaccharide extracted induced intrinsic apoptosis via up-regulation of caspase-3, caspase-9 and Bax along with down-regulation of Bcl-2 in HeLa cells.Conclusion: Taken together, the apoptosis inducing effect of brittle star polysaccharide via intrinsic pathway confirmed the anti tumor potential of marine polysaccharide. Therefore, these findings proposed new insight into anti cancer properties of brittle star polysaccharide as a promising agent in cervical cancer treatment.

Background: The chromogenic assay based on MTT bioreduction was adapted to Proteus mirabilis viability estimations. We primarily intended to use the assay for the evaluation of novel antimicrobial compounds, including structures with possible per-meabilizing activity. Therefore, the influence of basic permeabilizing agents like Triton X-100 and EDTA upon the MTT assay was studied.Methods: 3-(4, 5-Dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) was used as a substrate for the whole-cell dehydrogenase activity estimations. The amount of formazan product was evaluated in the end-point reactions terminated with acidic isopropanol or in the continuous reactions run in the presence of low detergent concentrations.Results: The generally established procedure of the end product dissolution with acidic isopropanol caused absorbance instability which strongly affected the results accuracy. The disadvantage was especially pronounced when the assay was conducted in Mueller-Hinton Broth. PBS with 0.01% Triton X-100 used as the reaction medium allowed to omit the formazan dissolution step and follow the microbial MTT reduction in a continuous mode. It was observed that in Proteus mirabilis with a compromised outer membrane the assay score was artificially increased above the untreated control.Conclusion: The dependence of the assay results on the cell integrity might be a major drawback of the MTT assay application for the evaluation of novel antimicrobials against Gram-negative microorganisms. On the other hand, the MTT reduction could be conveniently used to assay the permeabilization degree in biotechnological protocols.

Background: Cleft lip with or without cleft palate (CL/P) is one of the most common congenital anomalies and the etiology of orofacial clefts is multifactorial. Transforming growth factor alpha (TGFA) is expressed at the medial edge epithelium of fusing palatal shelves during craniofacial development. In this study, the association of two important TGFA gene polymorphisms, BamHI (rs11466297) and RsaI (rs3732248), with CL/P was evaluated in an Iranian population.Methods: The frequencies of BamHI and RsaI variations were determined in 105 unre-lated Iranian subjects with nonsyndromic CL/P and 218 control subjects using PCR and RFLP methods, and the results were compared with healthy controls. A p- value of <0.05 was considered statistically significant.Results: The BamHI AC genotype was significantly higher (Pp=0.016) in the patients (12.4%) than the control group (5.0%). The BamHI C allele was significantly higher (pP=0.001; OR=3.4, 95% CI: 1.6- 7.4) in the cases (8.0%) compared with the control group (2.5%).Conclusion: Our study showed that there was an association between the TGFA BamHI variation and nonsyndromic CL/P in Iranian population.

Background: The risk of developing female infertility has been associated with gene polymorphisms that decrease the activity of enzymes involved in systemic oxidative Oxidative stressStress (OS).Objectives: In this study, PON1 L55M polymorphism for association with susceptibility to infertility was investigated among Iranian female population.Materials and mMethods: Samples from 120 Iranian females [(20 endometriosis; 30 Ppolycystic Oovary Ssyndrome, (PCOS); 70 controls]) were analyzed and PCR-RFLP assay was used to determine the PON1 rs854560 (L55M) frequencies. The paraoxonase (PONase) and arilesterase (AREase) activities of PON1 enzyme were also assessed in order to investigate the association between serum PON1 activities, female infertility, and PON1 L55M polymorphism.Results: The women with a MM genotype (p=0.021; OR=2.55) showed more possibilities of experiencing infertility than those with a LM genotype (p=0.039; OR=1.91). According to LSD test, endometriosis subjects had significantly lower paraoxonase enzyme activity compared to control group (p=0.0024; CI=95%). No significant difference was found in women with PCOS for both PONase and AREase activity in comparison with control group (p=0.469; CI=95%). Furthermore, PON1 activities were the highest in LL genotype followed by LM and then MM genotype (MM<LM<LL) in both patients and controls.Conclusion: PON1 L55M polymorphism may be associated with serum PON1 activity and the risk of developing female infertility.

Background: CTLA-4 inhibitory signals prevent cell cycle progression and IL-2 production, leading to a halt on an ongoing immune response. CTLA4-Ig fusion proteins contain the extracellular domain of CTLA-4 and Fc fragment of human IgG antibody. In this study we aimed to fuse the ctla-4 gene encoding the extracellular domain of CTLA-4 molecule with igg1 gene encoding Fc region of human IgG.Methods: After primer design, PCR reaction was performed using pfu polymerase enzyme and specific primers. PCR amplified fragment was ligated into the vector containing the human igg1 gene. The resulting fusion fragment of ctla-4 and human igg1 genes was ligated to pBudCE4.1 expression vector.Results: Extracellular domain of ctla-4 gene was ligated to igg1 gene and then ctla4-ig fragment was cloned into pBudCE4.1 vector. Construction of the expression vector was confirmed by restriction pattern analysis and sequencing.Conclusion: By confirming the construct, in the next step, the recombinant DNA will be used to produce CTLA4-Ig recombinant protein for the clinical uses.