Teaching embryology to undergraduates in the Faculty of Education at Dokuz Eylul University in Izmir,Turkey

This report reviews the way in which classical embryology is taught and interpreted at the Buca Faculty of Education, in Dokuz Eylul University (Turkey). This university is one of the leading teacher-education institutions in Turkey. My course is taught with appreciation of the fact that students are thinking ideologically rather than scientifically with regard to creationism and evolution in both cognitive and educational processes. However, this ideological orientation, along with lack of classroom time and material resources, hinders my goal of a student-centered education. Being flexible with regard to philosophical and metaphysical issues on which concepts of evolution and creationism are in conflict, is constructive for student development and represents the approach I endeavor to pursue.     

Recovery of Cryptosporidium oocysts and Giardia cysts from source water concentrates using immunomagnetic separation

Immunomagnetic separation (IMS) procedures for the simultaneous isolation of Cryptosporidium oocysts and Giardia cysts have recently become available. We validated Dynal's GC-Combo IMS kit using source water at three turbidity levels (5000, 500 and 50 nephelometric turbidity units [ntu]) obtained from different geographical locations and spiked with approximately 9--11 (oo)cysts per ml. Mean recoveries of Cryptosporidium oocysts and Giardia cysts in deionized water were 62% and 69%, respectively. In turbid water matrices, mean recoveries of Cryptosporidium oocysts were between 55.9% and 83.1% while mean recoveries of cysts were between 61.1% and 89.6%. Marginally higher recoveries of the heat inactivated (oo)cysts were observed (119.4% Cryptosporidium oocysts and 90.9% Giardia cysts) in deionized water when compared with recoveries of viable (oo)cysts (69.7% Cryptosporidium oocysts and 79% Giardia cysts). Age of (oo)cysts on recoveries using the GC-Combo IMS kit demonstrated no effects up to 20 months old. Recovery of Giardia cysts was consistent for isolates aged up to 8 months (81.4%), however, a significant reduction in recoveries was noted at 20 months age. Recoveries of low levels (5 and 10 (oo)cysts) of Cryptosporidium oocysts and Giardia cysts in deionized water using IMS ranged from 51.3% to 78% and from 47.6% to 90.0%, respectively. Results of this study indicate that Dynal's GC-Combo IMS kit is an efficient technique to separate Cryptosporidium/Giardia from turbid matrices and yields consistent, reproducible recoveries. The use of fresh (recently voided and purified) (oo)cysts, aged (oo)cysts, viable and heat-inactivated (oo)cysts indicated that these parameters do not influence IMS performance.     

Tritrophic interactions between parasitoids and cereal aphids are mediated by nitrogen fertilizer

Host plant nutritional quality can directly and indirectly affect the third trophic levels. The aphid–parasitoid relationship provides an ideal system to investigate tritrophic interactions (as the parasitoids are completely dependent for their development upon their hosts) and assess the bottom up forces operating at different concentrations of nitrogen applications. The effects of varying nitrogen fertilizer on the performance of Aphidius colemani (V.) reared on Sitobion avenae (F.) and Aphidius rhopalosiphi (D.) reared on Rhopalosiphum padi (L.) were measured. Parasitism and percent emergence of parasitoids were positively affected by nitrogen fertilizer treatments while developmental duration (egg, larval, and pupal stages) was not affected by increasing nitrogen inputs. In males and females of both parasitoid species, adult longevity increased with the increasing nitrogen fertilizer. Hind tibia length and mummy weight of both parasitoid species increased with nitrogen fertilizer concentrations, as a result of larger aphids. This study showed that nitrogen application to the soil can have important consequences for aboveground multitrophic interactions.     

Iron Impregnated Activated Carbon as an Efficient Adsorbent for the Removal of Methylene Blue: Regeneration and Kinetics Studies

In this study, iron impregnated activated carbon (FeAC) was synthesized following an oxidation and iron impregnation of activated carbon (AC). Both the AC and FeAC were characterized by pH_ZPC and FTIR spectroscopy. The removal of Methylene Blue (MB) by AC and FeAC was examined under various experimental conditions. The FeAC showed up to 95% (higher than AC) MB removal in the pH range of 7–10. Although the reaction kinetics was pseudo–second order, the overall rate was controlled by a number of processes such as film diffusion, pore diffusion and intraparticle diffusion. The activation energy values for the MB uptake by AC and FeAC (21.79 and 14.82 kJ/mol, respectively) revealed a physisorption process. In the regeneration study, FeAC has shown consistently ≥ 90% MB removal even up to 10 repeated cycles. The reusable characteristic of the spent FeAC improved the practical use of activated carbon and can be a breakthrough for continuous flow system applications where it can work effectively without any significant reduction in its performance.     

Synthesis of a New Tri-Branched PEG-IFNα2 and Its Impact on Anti Viral Bioactivity

Efficacy of proteins can be enhanced by using polyethylene glycol (PEG) conjugation (PEGylation) to the protein molecules. Mobile non-toxic PEG chains conjugated to bio-therapeutics increase their hydrodynamic volume and in turn can prolong their plasma retention time and increase their solubility. An important aspect of PEGylation is the selection of PEG molecule with suitable structure and molecular weight. In this study, conceiving the idea that branched PEG-conjugates show superior efficacy over the linear PEG-conjugates, a tri-branched PEG-interferon (mPEG₃L₂-IFN) was synthesized by reacting a 30 KDa tri-branched mPEG₃L₂-NHS reagent with IFN to improve its pharmacokinetic properties and reduce the loss of in vitro bioactivity (which is generally exhibited by PEGylation) of the conjugated protein to some extent. The PEGylation procedure was optimized in terms of concentration and molar ratios of reactants, reaction time, temperature and pH conditions of the reaction mix. The conjugate was purified by cation exchange chromatography and characterized by SDS-PAGE and SE-HPLC. Trypsin digestion of mPEG₃L₂-IFN indicated a single site specificity of PEGylation. Anti viral bioactivity of mPEG₃L₂-IFN was found to be 2.38 × 10⁷ IU/mg which is approximately 9.52% of native IFNα2 (2.5 × 10⁸ IU/mg) and better than PEGasys from Roche Pharma. Therefore, it is reported that the tri-branched mPEG₃L₂-NHS reagent has the potential to be used to conjugate proteins for the promising therapeutic results.     

Identification of disulfide reductases in Campylobacterales: a bioinformatics investigation

Disulfide reductases of host-colonising bacteria are involved in the expression of virulence factors, resistance to drugs, and elimination of toxic compounds. Large-scale genome analyses of 281 prokaryotes identified CXXC and CXXC-derived motifs in each microorganism. The total number of these motifs showed correlations with genome size and oxygen tolerance of the prokaryotes. Specific bioinformatic analyses served to identify putative disulfide reductases in the Campylobacterales Campylobacter jejuni, Helicobacter pylori, Wolinella succinogenes and Arcobacter butzleri which colonise the gastrointestinal tract of higher animals. Three filters applied to the genomes of these species yielded 35, 25, 28 and 34 genes, respectively, encoding proteins with the characteristics of disulfide reductases. Ten proteins were common to the four species, including four belonging to the thioredoxin system. The presence of thioredoxin reductase activities was detected in the four bacterial species by observing dithiobis-2-nitrobenzoic acid reduction with β-nicotinamide adenine dinucleotide phosphate as cofactor. Phylogenetic analyses of the thioredoxin reductases TrxB₁ and TrxB₂ of the four Campylobacterales were performed. Their TrxB₁ proteins were more closely related to those of Firmicutes than to the corresponding proteins of other Proteobacteria. The Campylobacterales TrxB₂ proteins were closer to glutathione reductases of other organisms than to their respective TrxB₁ proteins. The phylogenetic features of the Campylobacterales thioredoxin reductases suggested a special role for these enzymes in the physiology of these bacteria. Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Disulfide-dependent protein folding is linked to operation of the vitamin K cycle in the endoplasmic reticulum. A protein disulfide isomerase-VKORC1 redox enzyme complex appears to be responsible for vitamin K1 2,3-epoxide reduction

Gamma-carboxylation of vitamin K-dependent proteins is dependent on formation of reduced vitamin K1 (Vit.K1H2) in the endoplasmic reticulum (ER), where it works as an essential cofactor for gamma-carboxylase in post-translational gamma-carboxylation of vitamin K-dependent proteins. Vit.K1H2 is produced by the warfarin-sensitive enzyme vitamin K 2,3-epoxide reductase (VKOR) of the vitamin K cycle that has been shown to harbor a thioredoxin-like CXXC center involved in reduction of vitamin K1 2,3-epoxide (Vit.K>O). However, the cellular system providing electrons to the center is unknown. Here data are presented that demonstrate that reduction is linked to dithiol-dependent oxidative folding of proteins in the ER by protein disulfide isomerase (PDI). Oxidative folding of reduced RNase is shown to trigger reduction of Vit.K>O and gamma-carboxylation of the synthetic gamma-carboxylase peptide substrate FLEEL. In liver microsomes, reduced RNase-triggered gamma-carboxylation is inhibited by the PDI inhibitor bacitracin and also by small interfering RNA silencing of PDI in HEK 293 cells. Immunoprecipitation and two-dimensional SDS-PAGE of microsomal membrane proteins demonstrate the existence of a VKOR enzyme complex where PDI and VKORC1 appear to be tightly associated subunits. We propose that the PDI subunit of the complex provides electrons for reduction of the thioredoxin-like CXXC center in VKORC1. We can conclude that the energy required for gamma-carboxylation of proteins is provided by dithiol-dependent oxidative protein folding in the ER and thus is linked to de novo protein synthesis.     

The possible role of 10398A and 16189C mtDNA variants in providing susceptibility toT2DM in two North Indian populations: a replicative study

The role of mitochondria in causing diseases is becoming evident as more and more studies are focusing on this organelle of the cell. This is largely attributed to its reactive oxygen species (ROS) production property. In the context of diabetes, ROS is suggested to trigger different forms of insulin resistance involving different mechanisms. The suggestive role of a mtDNA variant G10398A in increasing ROS production and the impaired response to oxidative stress due to T16189C variant is worth addressing as genetic susceptibility factors in type 2 diabetes mellitus (T2DM). A case control study on 312 T2DM cases and ethnically matched 466 controls involving two North Indian populations, referred as cohort 1 and cohort 2 (in a replicative study), was undertaken to test such a genetic association. A statistically significant association was observed for 10398A allele in both the cohorts [cohort1 (OR = 2.67 95% CI 1.77–4.00); cohort2 (OR = 1.76 95%CI 1.12–2.77)]. The analysis of G10398A/T16189C haplotypic combinations revealed that 10398A/16189C haplotype provides a risk in both the cohorts. To sum up the study suggests that 10398A and 16189C alleles provide susceptiblity to T2DM independently as well as together.