One of the major problems concerning the production of food crops is the controlling of plant diseases to maintain the high quality and yield. Wheat diseases are caused by parasitic bacteria, fungi and viruses that are a major hazard in wheat production. Therefore, understanding of any resistance mechanism is prerequisite for the successful utilization of wheat crop species in modern agriculture. The phenomenon of induced resistance by fungi, bacteria, microbial elicitors and chemicals has been investigated widely and resulted in many discoveries that conclude a general realization that the disease resistance signaling pathway in plants shares a number of common elements with those leading to innate immunity but a few of them have been characterized at the molecular level yet. Therefore our goal in this study is to identify genes activated or repressed after treatment of wheat plants with biological elicitor fungus, Trichoderma harzianum, and chemical inducers, benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester (BTH) and &szlig / -aminobutyric acid (BABA). mRNA differential display technique, which is a powerful tool to identify those genes that are differentially expressed between the two cell types has been extensively used in this study. The variety &#039 / Avocet S&#039 / is used to identify putative genes activated or repressed after treatment of wheat plants with biological elicitor fungus, Trichoderma harzianum, and chemical inducers, BTH and BABA comparing to untreated &#039 / Avocet S&#039 / wheat plants. The differentially expressed cDNA bands were cloned and sequenced. Nucleotide sequences of differentially expressed cDNA bands were searched in the Genbank. Sequence alignments between the fragments that represent a certain gene were also searched in ClustalX-1.81 computer programs. The sequences of the differentially expressed fragments were also confirmed by real time PCR that verify the gene expression differences observed between the biologically or chemically treated and untreated plants as a result of defense induction. The confirmed genes were found to be involved directly or indirectly in the induced disease resistance. These genes are important in terms of understanding the mechanism of systemic acquired resistance (SAR) signalling defense and helpful in producing transgenic wheat.

Conventional methods of chemotherapy requires novel therapy systems due to serious side effects and inefficiency of drug administration. In recent years many studies are carried out to improve drug delivery systems. Polymers are one of the most important elements for drug delivery research due to their versatility. By the discovery of dendritic polymers, drug delivery studies gained a new vision. Highly branched monodisperse structure, multiple sites of attachment, well-defined size and controllable physical and chemical properties make them efficient drug delivery systems. In this research hyperbranched dendritic polymers were sythesized and characterized for hydrophobic drug delivery. Dipentaerythritol which was used as core molecule, esterified with dimethylol propionic acid. Ricinoleic acid was esterified with the end groups of dimethylol propionic acid and hyperbranched resin (HBR) was formed. By considering the properties of HBR, hydrophobic tamoxifen and idarubicin were used for drug delivery study. The most efficient loading was determined as 73% for tamoxifen and 74% for idarubicin. Drug-HBR interactions and changes in properties of HBR were determined by FTIR, zeta potential and particle size measurements. FTIR results indicated that idarubicin chemically interacted with HBR while tamoxifen physically loaded to HBR. Drug delivery profile of HBR was studied in the absence and presence of lipase from Pseudomonas sp. and sodium dodecyl sulfate (SDS). Results revelaed that lipase and SDS increased the release rate of tamoxifen while idarubicin release rate was not affected. The effect of lipase was also tested for the degradation of HBR and it was indicated that lipase sustain a faster degradation. Finally toxicity of HBR and drug loaded HBR on MCF-7 breast cancer cell line was determined with XTT proliferation assay. Empty HBR did not cause significant toxicity on MCF-7 cells while drug loaded HBR was more toxic than free drug. By this study the efficiency of novel synthesized hyperbranched polymer in drug delivery was shown.

Thiopurine methyltransferase (TPMT) risk alleles (mainly *2,*3B, *3C and *3A) are the major determinants of interindividual differences in the severe toxicity or efficacy of 6-mercaptopurine (6MP) during the treatment of childhood acute lymphoblastic leukemia (ALL). The frequencies of these risk alleles, known to functionally impair TPMT activity, were investigated among 167children with ALL and 206 healthy adult controls in Turkish population by using allele specific PCR and PCRRFLP methods. TPMT*3A and TPMT*3C were the only deficiency alleles detected in Turkish population with an allele frequency of 0.5% for both. The total frequency of mutant TPMT alleles in Turkish population (1.0%) was found to be significantly lower than those of other Caucasian populations (5.3-7.0%), but it was found to be very similar to Kazak population (1.2%) which is also Caucasian in ethnic origin. v In the patient group, two individuals were found to be heterozygote for *3C and *3A allele. One individual was homozygous mutant (*3B/*3C). In this study, the clinical histories of the patients with TPMT defects were examined retrospectively from hospital records. The patients with heterozygous or homozygous mutant genotypes had systematically developed severe neutropenia, infection and some other specific conditions (like lesions around mouth, oral herpes and high fever) when they were administered with 6MP during the therapy. This study provides the first data on the frequency of common TPMT risk alleles in the Turkish population, based on analysis of pediatric patients with ALL. The results would contribute valuable information to the public health, as more clinicians and patients become aware of the importance of TPMT polymorphisms, less patients will suffer from 6MP related adverse effects. In addition, in this study two genes EPHX1-microsomal epoxide hydrolase (exon 3 and exon 4 polymorphisms) and SULT1A1*2 variant &ndash / sulfotransferase 1A1, either alone or in combination were investigated as risk modifiers in the development of childhood acute lymphoblastic leukemia due to their dual role (activation/detoxification) in the metabolism of various carcinogens. Also interactions of these polymorphisms with non-genetic risk factors (parental smoking exposure and parental age at conception) were investigated. The conclusion inferred from results was that only genetically reduced EPHX1 activity (homozygous mutant genotype for EPHX1 exon 3 polymorphism and some specific genotype combinations with exon 4 polymorphism) was found to be significantly associated with the risk of childhood ALL.

Resistance to anticancer drugs is a serious obstacle to cancer chemotherapy. A common form of multidrug resistance (MDR) is caused by the overexpression of transmembrane transporter proteins P-glycoprotein and MRP1, encoded by MDR1 and MRP1 genes, respectively. These proteins lead to reduced intracellular drug concentration and decreased cytotoxicity by means of their ability to pump the drugs out of the cells. Breast cancer tumor resistance is mainly associated with overexpression of P-gp/MDR1. Although some chemical MDR modulators aim to overcome MDR by impairing the function of P-gp, they exhibit severe toxicities limiting their clinical relevance. Consequently, selective blocking of the expression of P-gp/MDR1 specific mRNA through RNA interference strategy may be an efficient tool to reverse MDR phenotype and increase the success of chemotherapy. Aim of this study was re-sensitizing doxorubicin resistant breast cancer cells to anticancer agent doxorubicin by selective downregulation of P-gp/MDR1 mRNA. The effect of the selected MDR1 siRNA and MRP1 expression after MDR1 silencing was determined by qPCR analysis. XTT cell proliferation assay was performed to v determine the effect of MDR1 silencing on doxorubicin sensitivity.Intracellular drug accumulation and localization was investigated by confocal laser scanning microscopy after treatment with MDR1 siRNA or other MDR modulators / verapamil or promethazine. The role of P-gp in migration characteristics of resistant cells was evaluated by wound healing assay. The results demonstrated that approximately 90% gene silencing occurred by the selected siRNA targeting MDR1 mRNA. However the level of MRP1 mRNA did not change after MDR1 downregulation. Introduction of siRNA resulted in about 70% re-sensitization to doxorubicin. Silencing of P-gp encoding MDR1 gene resulted in almost complete restoration of the intracellular doxorubicin accumulation and re-localization of the drug to the nuclei. Despite the considerably high concentration of the modulators, verapamil and promethazine were not as effective as siRNA for reversal of the drug efflux. According to wound healing assay, MDR1 silencing did not have any effect on migration characteristics of resistant cells, that is, P-gp expression does not seem to affect the motility of the cells. Selected siRNA duplex was shown to effectively inhibit MDR1 gene expression, restore doxorubicin accumulation and localization, and enhance chemo-sensitivity of resistant cells, which makes it a suitable future candidate for therapeutic applications.

Hydrogels are three dimensional, insoluble, porous and crosslinked polymer networks. Due to their high water content, they have great resemblance to natural tissues, and therefore, demonstrate high biocompatibility. The porous structure provides an aqueous environment for the cells and also allows influx of nutrients needed for cellular viability. In this study, a natural biodegradable material, agarose (Aga), was used and semi-interpenetrating networks (semi-IPN) were prepared with polymers having different charges, such as positively charged chitosan (Ch) and negatively charged alginate (Alg). Hydrogels were obtained by the thermal activation of agarose with the entrapment of Ch or Alg in the Aga hydrogel structures. Chemical composition of hydrogels were determined by ATR-FTIR examinations, mechanical properties of hydrogels were examined through compression tests, morphologies were confirmed by scanning electron microscopy (SEM) and confocal microscopy, thermal properties were evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Moreover, swelling ratios, water contact angles and surface free energies (SFE) were determined. Cell proliferation and cell migration within these hydrogels were examined by using L929 fibroblast cell line. MTS assays were carried out to observe the cell proliferation on hydrogels. Confocal microscopy was used in order to examine the cell behavior such as cell attachment and cell migration towards the hydrogels. It was observed that addition of positively charged Ch into agarose increased the ultimate compressive strength (UCS), decreased elastic modulus (E), increased the thermal stability and hydrophobicity of the semi-IPN hydrogels. On the other hand, addition of negatively charged Alg into agarose decreased UCS, E, thermal stability and hydrophilicity. Cell-material interaction results showed that Aga hydrogels in tissue engineering applications was improved by adding different charged polyelectrolytes. Cell migration within Aga hydrogels was enhanced by adding Ch, and hindered by addition of Alg. Maximum cell proliferation and maximum penetration of the cells were obtained with the Ch/Aga hydrogels most probably due to attraction between the negatively charged cell surface and the positively charged Ch/Aga hydrogel surface. It was shown that cell interaction of agarose hydrogel scaffolds could be enhanced by introducing chitosan within the agarose hydrogels and obtained structures could be candidates for tissue engineering applications.

This study aims to find out major factors acting on steppe biodiversity of Inner Anatolia by focusing on one million hectares of mountainous land. Quantitative data on common plants, breeding birds and butterflies as well as environmental and land use data were collected at 33 sites determined by environmental stratification. Data has been analyzed with Spearman&rsquo / s rank correlation, canonical correspondence analysis, detrended correspondence analysis, two-way indicator species analysis and hierarchical partitioning. Results show that elevation, current grazing intensity, distance to woodlands and arable lands are the main determinants of richness and diversity. Other important factors are soil Magnesium and organic matter for plants / local heterogeneity and shrub/tree density for birds / plant richness and mud-puddling sites or wind shelters attracting butterflies. Altitude and grazing intensity have negative effects on biodiversity whereas soil Magnesium and proximity to other vegetation types have positive effects. In sites with more than 90% herbaceous coverage, shrub/tree density is a good indicator for the richness patterns of all groups. The richest sites are low mountain shrubby steppes close to woodlands and arable lands, ploughed 30-100 years ago but then abandoned and experienced light or no grazing afterwards. Six major plant communities are distinguished by gypsum bedrock, altitude and years since land abandonment. Four main bird assemblages are differentiated with landscape and local heterogeneity and composition and wood density of the sites. Various factors act on richness and diversity patterns on steppes, differing for species groups and assemblages. Conservation actions should encompass conservation priority species, represent different species assemblages, consider all major factors mentioned above especially landscape and local heterogeneity including different seral stages and sustaining conservation through nature-friendly land use. Planning afforestation in the way not to destroy rich steppes and building awareness on steppes as a value are important conservation actions.

High blood glucose levels induce metabolic disorders that initiate a sequence of events including renal, arterial, cardiac and retinal disorders. Diabetes mellitus increases oxidative stress in tissues of animals including humans. The resulting oxidative stress might play role in the development of diabetic complications. In the present study, 36 male Wistar rats (250-300g) were divided into 5 groups as Control (n=6), Diabetic (n=7), Diabetic + Vit C (n=7), Diabetic + &amp / #945 / -Lipoic acid (n=6) and Diabetic + Combination of Vit C and &amp / #945 / -Lipoic acid (n=10). From the livers of all groups cytoplasmic and microsomal membrane fractions were prepared from liver and antioxidant enzymes namely, superoxide dismutase, glutathione peroxidase, catalase and glutathione S-transferase activities were measured. Microsomal lipid peroxidation, total lipid, total protein, reduced glutathione levels of each group was determined and compared. Microsomal fractions were also analyzed by FT-IR spectroscopy. The total protein levels of diabetic rats were found to be decreased significantly (p&lt / 0.05) compared to controls and the &amp / #945 / -lipoic acid and vitamin C supplemented groups tend to compensate the decreased levels of total proteins. Decreased catalase activity in diabetic group compared to control was restored by &amp / #945 / -lipoic acid, vitamin C treatment and/or combination of both. Increased glutathione peroxidase activity was decreased to control levels by the treatement of both &amp / #945 / -lipoic acid and vitamin C. Superoxide dismutase activities of diabetic rats were increased (p&lt / 0.05) compared to control group. Whereas glutathione S-transferase activities though showed some fluctuations, the results were not statistically significant. Total glutathione levels decreased in all groups significantly (p&lt / 0.0.5) compared to control group but any of the agent failed to compensate the reduced levels of glutathione. As an index of lipid peroxidation, TBA-reactivity (MDA) levels increased significantly in all diabetic groups and only combination group&rsquo / s TBARS levels decreased significantly compared to diabetic group. FT-IR study of rat liver microsomal membranes was carried out in order to understand the effects of diabetes on membrane order, dynamics and lipid peroxidation status. For this purpose CH2 symmetric wavenumber, CH2 antisymmetric bandwidth, =CH olefinic band area were compared. In temperature dependent FT-IR studies microsomal membrane phase behavior, order and dynamics were analyzed. Diabetic samples showed apparent decrease in both frequency and bandwidth. =CH olefinic band integrated area was increased for diabetic samples compared to controls. Alpha-lipoic acid and vitamin C supplemented groups showed similar effects. They tend to restore decreased levels of band frequency and bandwidth. Additive effect between &amp / #945 / -lipoic acid and vitamin C was seen in some cases that only the combination group achieved to restore control values while &amp / #945 / -lipoic acid and vitamin C were failed to restore alone. In conclusion, STZ-induced diabetes mainly caused an increase in antioxidant enzyme activities. Also, increase in lipid peroxidation caused a decrease in the fluidity and order of the membrane resulting in more rigid membrane structures. The loss of cooperation between the antioxidant network may play a role in the secondary complications of diabetes.

The heart does not regenerate new functional tissue when myocardium dies following coronary artery occlusion, or is defective. Ventricular restoration involves excising the infarct and replacing it with a cardiac patch to restore the heart to a more efficient condition. The goal of this study was to design and develop a myocardial patch to replace myocardial infarctions. A basic design was developed that is composed of 3D microfibrous mats that house mesenchymal stem cells (MSCs) from umbilical cord matrix (Wharton&rsquo / s Jelly) aligned parallel to each other, and biodegradable macroporous tubings to supply growth media into the structure. Poly(glycerol sebacate) (PGS) prepolimer was synthesized and blended with P(L-D,L)LA and/or PHBV, to produce aligned microfiber (dia 1.16 - 1.37 &amp / #956 / m) mats and macroporous tubings. Hydrophilicity and softness of the polymer blends were found to be improved as a result of PGS introduction. The Wharton&rsquo / s Jelly (WJ) MSCs were characterized by determination of their cell surface antigens with flow cytometry and by differentiating them into cells of mesodermal lineage (osteoblasts, adipocytes, chondrocytes). Cardiomyogenic differentiation potential of WJ MSCs in presence of differentiation factors was studied with RT-PCR and immunocytochemistry. WJ MSCs expressed cardiomyogenic transcription factors even in their undifferentiated state. Expression of a ventricular sarcomeric protein was observed upon differentiation. The electrospun, aligned microfibrous mats of PHBV-P(L-D,L)LA-PGS blends allowed penetration of WJ MSCs and improved cell proliferation. To obtain the 3D myocardial graft, the WJ MSCs were seeded on the mats, which were then wrapped around macroporous tubings. The 3D construct (4 mm x 3.5 cm x 2 mm) was incubated in a bioreactor and maintained the uniform distribution of aligned cells for 2 weeks. The positive effect of nutrient flow within the 3D structure was significant. This study represents an important step towards obtaining a thick, autologous myocardial patch, with structure similar to native tissue and capability to grow, for ventricular restoration.