Volume 39 Issue 1

January 2011


TitlePages
Preface
Preface
Purification of Antibodies by Affinity Chromatography

Antibodies are becoming a dominant protein class for various human therapeutical applications and they represent the largest number of molecules in clinical trials today. Antibodies are purified using a combination of various purification techniques. The most popular technique is affinity chromatography based on specific interaction of immunoglobulin G (IgG) with affinity ligand. Affinity chromatography has several advantages since it is an easy, fast and selective procedure for capturing the target antibody. This review aims at describing different affinity techniques for purification of antibodies and reports the contributions of scientists working in this field and their important results. The main issues discussed in this review are: protein A affinity chromatography, histidine-ligand affinity chromatography, immobilized metal-chelate affinity chromatography, dye-ligand affinity chromatography, biomimetic affinity chromatography, negative chromatography, mixed-mode affinity chromatography, thiophilic chromatography, magnetically stabilized fluidized beds and aqueous two phase systems. 

1 - 18
Use of Bayesian Approach in Chemistry

Bayesian approach is a popular topic today in many fields of study in which statistics is used. The availability of stochastic simulation technique such as Markov Chain Monte Carlo makes exact Bayesian solution possible even in very complex and high dimensional models. The purpose of this short review paper is to emphasize the basic principles and to show the use of Markov Chain Monte Carlo technique for Chemistry data. 

19 - 22
Rapid Production of Highly Interconnected Porous Scaffolds by Spheroidized Sugar Particles for Tissue Engineering

Irregular pore morphology has a significant influence on cell response and the control of pore interconnectivity in the scaffolds constructed for tissue engineering of bone. In this study, we explored a new porogen for particulate leaching technique to fabricate highly interconnected porous scaffold with pores in regular shape. A polymeric blend composed of poly-L-lactide (PLLA) and poly-e-caprolactone (PCL) (with average molecular weights of 220 kDa and 50 kDa, respectively) was used for the construction of the scaffold. Spheroidized sugar particles were produced by using a flame treatment with a Meker burner. This method enabled the formation of homogenous and symmetrical particles with high water solubility. A pigment was blended into this polymeric mixture to investigate the morphology by confocal microscopy. The fabricated scaffolds were thoroughly characterised physically and biologically. Porosity and average pore size values were calculated by m-CT as 83% and 312 mm respectively. Live/ dead assay by confocal microscopy demonstrated high cell attachment and cell viability in the scaffolds. This new scaffold fabrication method will be useful for tissue engineering community in the control of scaffold architecture. 

23 - 28
Organic Farming By Using Saharan Soil: Could It Be An Alternative To Fertilizers?

It has been shown that Saharan soil may have the potential of producing bioavailable iron when illuminated with visible light and also it has some essential macro and micro nutrient elements. In this study the impact of various growth media on development of some bread wheat (Triticum aestivum L.) and durum wheat (Triticum durum L.) cultivars have been investigated. As a four different nutrient media, Hewitt nutrient solution [1], illuminated and non-illuminated Saharan desert soil solutions and distilled water have been utilized. Shoot length (cm.seedling-1), leaf area (cm2 seedling-1) and photosynthetic pigments [chlorophyll a, chlorophyll b and carotenoids, mg ml-1 g fresh weight (g fw)-1] have been determined. The results of this study indicate that, wheat varieties fed by irradiated Saharan soil solution gave comparable results to Hewitt nutrient solution. 

29 - 37
Partial Purification of Protease by A Novel Bacterium, Bacillus cereus and Enzymatic Properties ​

Proteases (E.C. 3.4.X.X) catalyze the hydrolysis of peptide bonds in proteins. Microbial proteases are classified based on their mode of action and biocatalytic mechanisms. They participate in most aspects of cell nutrition, physiology, and regulation, and in microbial pathogenesis. Protease production was detected from 15 bacteria isolated from soil samples and the one showed the highest protease activity was selected. The strain was identified and determined as Bacillus cereus by 16S rRNA phylogenetic analysis. After optimization of protease production from the novel medium, the Michaelis-Menten kinetics was studied. Temperature, pH and, time parameters of protease incubation was determined and maximum temperature was detected at 50oC as 5.15 IU/ml. The optimum pH range of the enzyme was in between pH 7-9. The crude enzyme was approximately 2-fold purified by dialysis. 

39 - 44
Plant Wildlife and Threatened Vascular Flora of Truva (Troy) National Park, Turkey

This paper deals with the floristic study of Truva National Park (Çanakkale/Turkey). Thus floristic specializa- tion of this area described, including a number of endemic and threatened species. After identification of the specimens, total flora has been determined as 361 taxa belonging to 354 species, 245 genera and 70 families. The endemism rate of the area is 3.32% (12 taxa). In a study of the endangered flora and its protection, 15 taxa are listed as having the most restricted distribution and as being under threat of extinction. Field work for these taxa was undertaken in order to improve knowledge of their habitats, populations, chorology and main threats. Using the new IUCN categories of threat, an analysis was made for each of the taxa, especially those that are critical endangered with very low number of individuals or very narrow areas of occupancy. In order to conserve the biological diversity of Truva, the need for more nature reserves, especially in the Yenikumkale, Orhaniye and Truva region is highlighted. A number of key strategies for protection are proposed. 

45 - 50
Allozyme Variations on Subspecies of Meriones tristrami (Rodentia: Gerbillinae) In Western Anatolia ​

Allozyme variation was investigated by the electrophoretic analysis of 24 gene loci in three subspecies of Meriones tristrami from Western Anatolia. Twenty of the twenty-four loci were monomorphic among populations, whereas four loci were polymorphic. The mean value of the Wright’s fixation index was FST = 0.0671, suggesting the existence of a slightly distinct subspecies in the Meriones tristrami populations. Overall mean heterozygosity (Ho= direct count) for all populations was Ho= 0.017. Nei’s measure of genetic distance was low and varied from D = 0.000 to 0.002 among populations. The number of migrants (Nm) equaled 3.48, which also suggests effective gene flow across populations.. 

51 - 56
Antifungal Effects of Clitocybe odora (Bull.: Fr.) Kumm. Against The Plant Pathogen Fusarium culmorum and Fusarium moniliforme

In this study, Clitocybe odora were dried under aseptic conditions and put thru extraction for 12 h in solvents. The extracts were filtered and dried using a rotary evaporator at 60°C and finally dried material stored +4°C. Antifungal activities were measured by Disc Diffusion method. According to this method; Fusarium culmorum and Fusarium moniliforme inoculums containing were spread on potato dextrose agar. The Clitocybe odora extracts were used to 6 mm discs as 10 μl. All these discs placed on the inoculated agar separately and incubated at 28°C for 48 h. For control, water and only acetone and chloroform saturated discs were used. Also in this study erythromycin and amoxycillin that commercial antibiotics were used for comparison. 

57 - 60
Effect of Salt Stress Induced by NaCl on Safflower (Carthamus tinctorius L.) Cultivars at Early Seedling Stages ​

Salinity is one of the major problems to affect plant growth and development in arid and semi arid regions. The reasons of the formation of the salty soil are climatic factors, weathering of parental rocks, oceans and using salty water for irrigation. In this study, the effect of different salt concentrations [0 (control), 75, 150, 225 and 300 mM NaCl] on the germination and early seedling stage of the three safflower (Carthamus tinctori- ous L.) cultivars (Dinçer, Remzibey-05 and Yenice) which are registered cultivars of Turkey were investigated. By the experimental study it was reported that safflower cultivars were negatively affected from different NaCl concentrations at early seedling stages and also, some differences at their salt tolerances to compare each others. Thus, it is suggested that safflower is moderately salt tolerant plant and safflower cultivars may be classified as tolerant (Yenice), moderately tolerant (Dinçer) and sensitive (Remzibey-05) by evaluating results obtained from both stage. 

61 - 64
Voltammetric Determination of Ethanol by Using Mushroom (Agaricus bisporus) Tissue Homogenate-Based Biosensor ​

Anew biosensor based on mushroom (Agaricus bisporus) tissue homogenate was developed for voltammetric determination of ethanol. Mushroom (Agaricus bisporus) was homogenated and immobilized onto the glassy carbon electrode via gelatine and cross-linked by glutaraldehyde to construct an electrochemical tissue homogenate based biosensor system. The homogenate contains alcohol oxidase (E.C 1.1.3.13) enzyme and it catalysis the degredation of ethanol to acetaldehyde and hydrogen peroxide. Assay principle of the biosensor based on the detection of reduction peaks of oxygen by using cyclic voltammetry at potentials between 0.0 and +0.7 V. To obtain a standard graphe for ethanol differential pulse (DP) method was used at potentials between +0.1 and +0.4 V. The electrode response depends linearly on ethahol concentration between 1.0 and 10.0 mM. Phosphate buffer (pH 7.0, 50 mM) and 30°C were obtained as the optimum conditions. In characterization studies of the biosensor some parameters such as; repeatability, substrate specificity, interference effects of some substances on the biosensor response were investigated. Finally, the proposed system was applied to ethanol detection in different wine and beer samples. 

65 - 70
Systematic Studies on The Male Genital Organs of Central Anatolian Elateridae (Coleoptera) Species Part I: The Subfamilies Elaterinae and Melanotinae

Taxonomical studies on the family Elateridae were mainly condensed on morphological characters. In palearctic region, most comprehensive studies were done in France, Armenia, Italy, Czech and Slovak Republics, Poland. These studies, which cover male genital organ structures, are systematical researches. In this study, male genital organs of Central Anatolian species of the subfamilies Elaterinae and Melanotinae were examined. Morphology of male genital organs were drawn in detail and described. Male genital organ structures of Adrastus circassicus and Melanotus (s.str.) bajulus were examined in detail for the first time. According to male genital organ morphologies, systematical status of examined species are discussed. 

71 - 82
Thrombocyte Indices in Pediatric Age Group

Platelet (PLT) indices mean platelet volume (MPV), platelet hematocrit (PCT) and platelet distribution width (PDW) are probably the most ignored parameters by the clinicians. Although several studies held among different disease states, they do not have diagnostic value yet. Our aim was to determine the reference range of platelet parameters in venous blood samples of a population with an age range 6 months to 18 years in a hospital laboratory. This retrospective study consisted of 710 healthy children and the subjects were categorized into five groups according to their age. Age distribution of these groups was 6 months; 12 months; 18 months; 2-5 years and 6-18 years respectively. Our data revealed significant differences with regard to the MPV, PCT and PDW among the groups (p<0.001). Also, it was found that the increased PLT count was statistically associated with an elevated PCT value (r = 0.91, p < 0.0001) and the number of PLT correlated negatively with MPV (r = -0.38, p < 0.001). PDW showed a positive correlation with MPV (r = 0.3, p < 0.001), but negatively with PLT (r= -0.2) and PCT (r = -0.1) (p < 0.001). Our data revealed that determination of the PDW reference range is fundamental, and the association of this parameter with the platelet number and mean platelet volume may be used for the diagnosis and differentiation of several pathologies. 

83 - 86
Thioredoxin Reductase

Thioredoxin reductase (TrxR, EC 1.6.4.5) is a homodimeric flavoenzyme that catalyzed the reduction of the thioredoxin (Trx). It has been characterized in many bacteria and mammalian organism and categorized under two different types: bacterial and mammalian. Mammalian TrxRs contain an essential selenocysteine residue in the conserved C-terminal sequence. Mammalian TrxRs have three isoforms; cytosolic, mitochondrial and testis-specific. TrxR3, as testis-specific form, have different property than the other mammalian TrxRs. TrxR is involved in many cellular functions including DNA synthesis, redox signaling, antioxidative defence, selenium metabolism and regulation of apoptosis. Because of the many known functions, it is not surprising that this enzyme is a major subject of the many research. TrxR has been purified and characterized from a wide variety of species by using ion-exchange and affinity chromatographies. Notably, TrxR is a target enzyme for cancer drug research due to the relation with apoptosis. In this review we will present the intra- and extracellular biochemical functions of the enzyme and important medical applications in drug development. 

87 - 92
  • ISSN 1303 5002
  • © 1973-2018 Hacettepe University