ramezan ali khavari-nejad

The production of biotechnological drug proteins plays an important role against disease. The process of producing drug recombinant proteins is not a direct path, because it requires a lot of work and on the other hand, one of the important and significant aspects in the production of proteins is the discussion of their stability and solubility during the expression and purification process. Proteins are stable only in a limited range of temperature and acidity conditions and are highly susceptible to physical and chemical degradation. Today, various solutions have been proposed to increase the solubility and stability of proteins, including guided changes in the protein molecule, and optimization of the instructions for expression, purification and solubility of proteins, which is often the first approach that is not possible. This review article provides solutions to increase the stability of proteins at different levels, including the study of the effect of expression construct design, protein tags and sequences on stability, optimal host cell selection and improved expression conditions. The effect of optimizing buffers used in pharmaceutical formulations such as selecting appropriate amino acids and osmolytes to increase protein stability and how sugars and polyols affect the stability of recombinant pharmaceutical proteins is also investigated.

Background &

Nowadays, high consumption plastics such as polyethylene are         recognized as one of the major environmental pollutants by the World Environment Organization. The aim of this study was to isolate and identify native Pseudomonas bacterial strains with the polyethylene packaging degradation ability.Materials &

In order to conduct this study, soil samples were collected. In order to    isolate the isolates with polyethylene degradation ability, two methods of direct culture and       culture by pre-enrichment method were used. After culturing the bacteria in MSM medium and examining the percentage of plastic weight loss, the superior strain was selected for DNA          extraction and PCR of alk-B gene. PCR results were sequenced and examined phylogenetically.

The results of the present study showed that the percentage of degradation of                polyethylene by Pseudomonas strains was 7.2% at most and 4.5% on average. Also, all purified degrading bacteria in this study harbored alk-B gene.

The results showed that the degradation of polyethylene materials can be                significantly accelerated by using and optimizing bacteria isolated from soil. It seems that by     promoting genetic methods based on the genome of bacteria, especially the strain of               Pseudomonas aeruginosa, it is possible to develop methods during which all commonly used types of polyethylene are degraded in a much shorter time than normal.

 Malaria is one of the most life-threatening infectious diseases worldwide. Transmission of the parasite from human to vector mosquitoes is carried out by the gametocyte of the Plasmodium parasite, while these cells are not involved in the symptoms of the disease. The control of the human to mosquito  transmission stage of the parasite life cycle by antigametocyte drugs is currently under increasing scrutiny in an effort to eradicate the disease globally. In this study the gametocytocidal activity of eosin B on asexual blood stages and gametocytes of Plasmodium falciparum has been probed.

The parasite Plasmodium falciparum 3D7 was first cultured and then  gametocytogenesis was induced to obtain gametocyte cells. After microscopically studying the developmental stages of the parasite during the culture of the parasite, eosin B was tested on blood and sexual parasites and the viability was assessed by lactate dehydrogenase assay and the results were compared for the two groups.

Mature gametocytes were produced during 12 days. The blood parasites in culture were increased until day 4 and then gradually diminished. The results of lactate dehydrogenase assay showed a stronger effect of eosin B on gametocytes (IC50 = 23 nM) than asexual blood stages (IC50 = 133 nM).

Due to the rarity of anti-gametocyte drugs and importance of these intervention on malaria elimination, eosin B appears to be a suitable candidate for combination therapy against Plasmodium falciparum gametocytes.

Non-invasive prenatal testing (NIPT) as a novel screening method has been widely proposed to screen for common fetal chromosomal aneuploidies. The aim of the present study was to examine the possible effects of maternal age, maternal weight, fetal crown-rump length (CRL), serum pregnancy-associated plasma protein A (PAPP-A), free beta-human chorionic gonadotropin (free β-hCG), and fetal gender on cell-free fetal DNA (cffDNA) percentage fluctuations.

In the present cross-sectional study, 308 singleton pregnant women aged 20-47 years at 11+0 to 13+6 weeks of pregnancy referring to the DeNA Laboratory in Tehran, Iran, for NIPT test during a one-month period between July 2018 and August 2018 were selected randomly. The cffDNA was extracted from maternal plasma. Whole exome sequencing by a ion semiconductor sequencer using cffDNA was applied for all participants. The PAPP-A and free β-hCGas biochemical biomarkers were assessed using a closed chemilumine scence immunoassay analyzer. The Shapiro-Wilk test, Pearson analysis, beta regression analysis, and Mann-Whitney U test were performed to analyze the data.

In the screening population, the cffDNA percentage showed no significant correlation with CRL and maternal age (P=0.096 and P=0.881, respectively). However, the cffDNA percentage correlated well with maternal weight, PAPP-A, and free β-hCG (P=0, P=0.009, and P=0.001, respectively). Beta regression between cffDNA percentage and maternal weight, free β-hCG, and PAPP-A was significant (P<0.001). The mean cffDNA percentage between male and female fetal groups showed a significant difference (P<0.001).

This study demonstrated that the cffDNA percentage in the first trimester of pregnancy had a negative correlation with maternal weight and a positive correlation with PAPP-A and free β-hCG values. Furthermore, the cffDNA percentage in male fetuses was higher than that in female fetuses.

Pregnancy-associated plasma protein-A (PAPP-A) and free β-human chorionic gonadotropin (free β-hCG) as valuable biochemical biomarkers are used to screen down syndrome, Edwards syndrome, and Patau syndrome in the first trimester of pregnancy. Closed immunoassay analyzers are regarded as sophisticated platforms to measure biochemical biomarkers. This study compared the performance of three chemiluminescence analyzers when used for combined screening.

The present cross-sectional study was conducted on 371 pregnant women within the age range of 20-47 years during 11+0 to 13+6 weeks of pregnancy referring to Dena laboratory in Tehran, Iran, during July 2018 and August 2018 using random selection. The biochemical biomarkers of PAPP-A and free β-hCG were assayed on Cobas, Immulite, and Maglumi analyzers. Benetech software as a commercial screening software was used to calculate the risks of trisomy 21 (T21), trisomy 18 (T18), and trisomy 13 (T13). Deming regression, nonparametric spearman analysis, analysis of variance, and Chi-square test were performed to analyze the data.

For the screening population, although the three systems well correlated to PAPP-A and free β-hCG, the values of Maglumi were slightly higher than those reported for Cobas and Immulite. The multiples of the median (MoM) of PAPP-A and free β-hCG had a significant correlation on three platforms. There were no significant differences between the calculated risks of T21, T18, and T13 on the three systems. The sensitivity for all systems was reported as 50%. In addition, specificity and negative predictive value (NPV) were higher than 99% and 95%, respectively. Positive predictive value (PPV) was reported as less than 50%.

The obtained results of the present study demonstrated that there were significant correlations between three different systems in terms of PAPP-A and free β-hCG values and MoMs. The sensitivity of all systems for all trisomies was 50%; however, the specificity of all systems was almost the same. The best PPV and NPV for T21 were on Cobas, Immulite, and Maglumi, respectively. The PPV and NPV of all systems for T18/13 were almost the same.

Recently eosin B was shown to have an effect on the asexual stage of Plasmodium falciparum and in this study, its activity against gametocytes and changes in the culture medium metabolites were investigated using an1HNMR-based metabolomics approach.

In the Biochemistry Department of Pasteur Institute of Iran in 2017, parasites were cultured and gametocytogenesis induced by heparin and 5% hematocrit. Sexual stage parasites were tested by eosin B in 90 well plates and IC50 determined using Lactate Dehydrogenase assay. Gametocytes were treated by IC50 dose of eosin B and the medium collected in the two groups: with eosin B and controls and sent for 1HNMR spectroscopy. The spectra were analyzed on MATLAB interface and the altered metabolites in the culture medium and eosin-affected biochemical pathways were identified by Human Metabolome Database and Metaboanalyst website.

The results revealed eosin B had an effective gametocytocidal activity against P. falciparum. The significant metabolites changed in the medium were thiamine, Asp, Asn, Tyr, Lys, Ala, Phenylpyruvic acid, NAD+ and lipids. The main pathways identified were aminoacyl-tRNA biosynthesis, Phenylalanine, tyrosine and tryptophan biosynthesis, Alanine, aspartate and glutamate metabolism, Phenylalanine metabolism, Nicotinate and nicotinamide metabolism, and lysine degradation.

Eosin B exhibited substantial gametocytocidal activity and affected important drug targets in the Plasmodium.

Drought stress is a major factor that reduces growth, development and production of plants especially in generative phase. Among crop plants, wheat (Triticum aestivum), which often experiences water-shortage conditions, is an appealing study system because there are so many natural genotypes differing in drought tolerance. Wheat as well as the most cereals is especially threatened by water deficit during flowering and grain filling period in relation to decreasing yield potential (Khanna-Chop and Selote., 2007). Phytohormones play an important role in plants tolerance of abiotic stresses by mediating a wide range of adaptive responses although some of them act differently. Abscisic acid (ABA) and cytokinin (CK) are two antagonist hormones that play useful roles when stresses as drought appear. But, recent data implied that abscisic acid (ABA)/CK ratios in xylem sap are important for stress signaling. Therefore, this experiment was established to study and compare the influence of exogenous treatments of individual CK and ABA and also CK and ABA interaction on flag leaves relative water content (LRWC), chlorophyll florescence and gas exchange in related to yield were studied in Triticum aestivum cv. Pishgam (drought-tolerant) and cv.MV-17 (drought-sensitive) under irrigation and drought conditions after post-anthesis stage.
The influence of CK, ABA and their combination CK/ABA on LRWC, photochemical efficiency and gas exchange in Triticum aestivum cv. Pishgam (drought-tolerant) and cv.MV-17 (drought-sensitive) flag leaves and yield under irrigation and drought conditions during the grain-filling period. Factorial experiment was based on based on split plot in a randomized complete block design with three replications. Chlorophyll fluorescence as photochemical efficiency was assayed by OS1-FL, a pulse modulated fluorometer (OptiScience Corporation, Tyngsboro, MA). Gas exchange traits were determined at flowering using a portable gas exchange measuring system (Li 6400, Li-Cor, USA). For yield assay, 60 plants were selected randomly to assess grain weight 1000 and grain yield per plant. One-way ANOVA was applied to determine the significance of the results between different treatments and then Duncan multiple range tests (p Drought stress decreased LRWC in Pishgam cv. more than MV-17, significantly. Among hormonal treatments, the interaction of CK and ABA increased LRWC in both cultivars, significantly more than other hormonal treatments during drought stress. Chlorophyll florescence results showed that ФPSII and qP decreased and NPQ increased significantly in sensitive cv. more than tolerant cv. when irrigation was interrupted. CK and ABA interaction increased Fv/Fm, ФPSII and NPQ more than other hormonal treatments. Also CK/ABA application caused the significant increment in qP in Pishgam cv. Stomatal conductance (gs), net photosynthesis (A), transpiration (E) and Mesophyll conductance (MC) decreased in both cultivars when drought occurred while sub-stomatal CO2 concentration (Ci) and photosynthetic water use efficiency (PWUE) increased. These changes were more significant in sensitive cv. than tolerant cv. CK and ABA interaction increased Ci, A and PWUE in both cv. more than other hormonal treatments, while ABA treatment was the most effective hormonal treatment in reduction of gs, E and MC under drought condition. Yield reduced in both cultivars when drought stress appeared. Yield reduction was more in sensitive cv. CK and ABA combination was the most effective treatment for increment of yield, especially in sensitive cv. under drought stress. More Physiologic damages and yield reduction under drought exposure in susceptible cultivars were reviewed in the previous study (Chaves et al., 2003). CK effects on chlorophyll stability, protein synthesis in chloroplast and ABA effects on reduction of oxidative damage in photosynthesis system under drought and salt stress are reasons for production efficiency in plants (Pospisilova, 2003; Pospisilova et al., 2005). óAlso assesment of correlation coefficient showed the most significant relation between NPQ, A and PWUE with 1000-grain weight and grain yield.
It seems that CK and ABA combination is the best treatment in related to improvement of chlorophyll florescence, photosynthesis and yield efficiency in both cultivars under drought stress. Also, MV-17 (sensitive cv.) could use the hormonal treatment better than Pishgam (tolerant cv.) to improve photosynthesis and yield stability.

With increasing consumer awareness, demand for sugar-free products and also products containing probiotic bacteria has been increased in recent years. As a result, the formulation of a non-fermented product which can be a suitable carrier for probiotic bacteria, as well as reduced sugar intake, is of particular importance. The purpose of this study was to formulate and commercialize a kind of sugarless probiotic chocolate dessert containing date sugar. For this purpose, 17 treatments were prepared according to the experimental design (RSM: Response Surface Methodology) and were kept in the refrigerator until the tests were performed on days 1, 11 and 21. The results showed that probiotic viability decreased with increasing date sugar content and storage time, but did not reach to 107 cfu/g (p

Water scarcity causes rice yield loss more than 30% under drought stress at field conditions. Hence, employing drought tolerant cultivars in this condition is an effective way to overcome such a challenge. Therefore, in current research, we have used three Iranian rice cultivars named Amol3, Sang-tarom and Neda, which is originated from a cross between Amol3 and Sang-tarom, in order to investigate responses of the selected rice cultivars to drought stress. In this study, several important physiological characteristics were evaluated under drought stress during a growth period. Therefore, present study was aimed to achieve some information about mechanisms and responses to drought stress and to use them in identifying tolerant cultivars in drought stress situation as well as employ them in rice breeding program.
The rice seedlings of three genotypes were tested at greenhouse under three levels of water treatments as: control (FTSW=1.0, Fraction of Transpirable Soil Water), mild drought stress (FTSW=0.5) and severe drought stress (FTSW=0.2) in four replications in 28±2ºC in day and 25± 2º in night and in 14 L/10 D light period in a factorial arrangement of treatments in randomized complete block design in PVC pipes with 1-meter-long and 10 cm in diameter. The root length, stomatal aperture size, ABA content in leaves and wet and dry weights of panicles were measured as essential features in these cultivars in both drought stress levels and in control treatment. For data analysis SPSS and SAS software was applied.
In this study, we found that in rice cultivar Neda, showed a significant reduction (P In Neda, no significant reduction was observed in stomatal aperture size while the maximum dry and fresh weights of panicles was found in Neda under mild drought stress condition, which could be a remarkable sign among the cultivars in long-term drought stress. A total of 30% reduction was observed for grain yield of Neda while the yield loss for Amol3 and san-tarom were 58% and 50%, respectively. Reduction in ABA level in leaf, root length stimulation and stomatal aperture size regulation could be assigned to the behaviors in highly tolerant cultivars under drought stress condition. Neda showed more similar responses to Amol3, one of its parent, than to Sang-tarom regarding increasing in root length and reduction in ABA level in leaf in response to drought stress. A good correlation between root length and reduction in ABA level or redistribution of ABA in root for better hydraulic conductivity and also preventing ethylene action in drought stress that needs to be more studied.

The aim of this study was to investigate the adaptation of the cyanobacterium Fischerella sp. ISC 107to combined effects of carbon dioxide concentration, acidic and alkalinity. Axenic strain was incubated in BG0-11 medium. Carbon dioxide treatments were limited and relatively non-limited. Acidic (pH 5), neutral (pH7), and alkaline (pH 9) conditions were employed in each treatment. Survival, growth, chlorophyll, phycocyanin, allophycocyanin, and phycoerythrin contents were evaluated in each treatment along with ammonium liberation, frequency, and biometry of heterocyst. Results showed that like other explored stigonematalean and nostocalean cyanobacteria, this strain cannot grow in acidic condition. Under limited carbon dioxide condition, difference in growth rates were not significant between acidic and alkaline conditions; however, carbon dioxide enrichment caused significant increase in growth rates. Phycobilisome system of this strain lacked phycoerythrin and may complete its structure both at the core and the rod under alkaline condition. Heterocyst frequency and biometry were maximum at alkaline condition showing significant correlation with nitrogenase activity. Heterocyst showed cylindrical and sub-cylindrical morphology on days 4and 5 after inoculation. Overall, the results showed that this strain may be qualified to be used as a biofertilizer similar to the other cyanobacteria.

Heavy metals are defined as the group of elements with an atomic density greater than 5 gcm-3. Existence of heavy metals can affect growth and physiology of plants. Chromium is a transition metal located in group VI-B of the periodic table that is the seventh and most abundant element on earth and a highly toxic non-essential metal for microorganisms and plants. This study was performed in a complementary randomized design with six level of chromium (0, 10, 25, 50, 75 and 100 mg kg-1) and four replication, in the research greenhouse of the Kharazmi University. Results indicated that increasing of chromium concentration significantly decreased the dry weight and fresh weight of shoots and roots. Moreover Chla, Chlb, Chl(a+b), carotenoids contents, growth ratio and RWC significantly decreased in the whole plants with increasing potassium dichromate, whereas flavonoids and anthocyanins were increased. The results indicated that proline amount of shoots and roots was were increased.

Cyanobacterium Arthrospira (Spirulina) platensis is a filamentous blue-green algae which has many nutritional and medicinal values for humans and animals. The present study investigated the effect of light intensity and pH on the productions of protein، fat، chlorophyll a and carotenoids in Spirulina platensis. Pure sample of Spirulina was grown in BG-11 liquid culture medium under the influence of three optical intensities including 1500، 1000 (control)، and 500 Lux and five pH treatments including 5. 1، 6. 1، 7. 1 (control)، 8. 1، 9. 1 and fintensity had a statistically significant impact on the amount of fat production in the cyanobacterium. However، no significant difference was observed in the amounts of the protein and photosynthetic pigments productions. The results of investigating the influence of pH changes in Spirulina platensis indicated that alkaline pH was more suitable in the productions of fat and protein than neutral pH and resulted in a significant increase in the amount of these compounds in cyanobacterium Spirulina.

In order to evaluate of physiological traits، related to drought tolerance، an experiment was carried out in controlled condition. The experiment was conducted to assess the effect of drought stress on photosynthesis، chlorophyll fluorescence and photosynthetic pigments in two tolerant genotypes (MCC392 & MCC877) and two susceptible genotypes (MCC68 & MCC448) were grown in drought stress (25% field capacity) and control (field capacity) conditions in the seedling، early flowering and podding stages and so evaluated base on factorial experiment based on completely randomized design with four replications. Drought stress significantly decreased CO2 assimilation rate (A)، transpiration rate (E)، and PSΙΙ photochemical efficiency (Fv/Fm) in all genotypes. Drought stress increased chl b in all investigated stages. In all investigated stages، water use efficiency (WUE)، A and Fv/Fm were higher in tolerant genotypes than that of susceptible genotypes under drought stress. Our results indicated that water use efficiency، A and Fv/Fm could be useful markers in the studies of tolerance to drought stress and screening of adapted cultivars of chickpea under drought stress.

Selenium has not been classified as an essential element for plants, in contrast to many other organisms. With the aim of evaluating the effects of different levels of selenium on metabolism in soybean plants (Glycine max L.), the present research was conducted. Selenium was foliarly applied in three levels (0, 25, 50mgl-1), three times with week intervals. The results showed that the application of Se had significant enhancing impacts on antioxidant enzymes (ascorbate peroxidase and catalase) as well as protein in both root and leaf tissues, especially in the later one. The application of selenium resulted in the increased total chlorophyll contents with the highest amounts observed in Se50-treated plants. Similarly, the improved contents of reducing sugars were resulted from the foliar supplemented selenium. the obtained results from the current study indicated that the utilization of se at these levels had inducing effects on the activities of antioxidant enzymes, protein content and chlorophyll amounts, thereby improving the plant resistance against various abiotic stress conditions.

The aim of this study is to determine the prevalence and genotype of human caliciviruses among children suffering from acute gastroenteritis referred to Masih Daneshvari Hospital. Human caliciviruses have been recognized as the major viral cause of acute gastroenteritis in all age groups worldwide. Studies revealed that the noroviruses and sapoviruses could be divided into five genogroups.Patients and A total of 47 fecal samples were collected from children up to 17 years of age, with acute gastroenteritis from 2006 to 2008. RT nested- PCR was performed for screening. To genotype the norovirus and sapovirus isolates, some positive samples were subjected to phylogenetic analysis by sequencing of fragments of viral capsid gene region. The noroviruses and sapoviruses were detected in 21.3% and 2.1% of samples, respectively. The phylogenetic analysis revealed that isolates belong to genotype GII.4 and GII.3. The sole isolate of sapovirus belongs to GI/2 genogroup. Our results show that calciviruses are indeed a major cause of acute gastroenteritis in children.