Cross - cultural adaptation and preliminary validation of the Turkish version of the Early Childhood Oral Health Impact Scale among 5-6-year-old children

<p>Abstract</p> <p>Background</p> <p>In Turkey, formal pre-primary education for children 5- 6 years old provides the ideal setting for school-based oral health promotion programs and oral health care services. To develop effective oral health promotion programs, there is a need to assess this target group's subjective oral health needs as well as clinical needs. The Early Childhood Oral Health Impact Scale (ECOHIS) is a well-known instrument for assessing oral health quality of life in children aged 0-5 years old and their families. This study aimed to adapt the ECOHIS for children 5-6 years old in a Turkish-speaking community and to undertake a preliminary investigation of its psychometric properties.</p> <p>Methods</p> <p>The Turkish version of the ECOHIS was obtained with forward/backward translations, expert panels and pre-testing and it was tested in a convenience sample of 121 parents of 5- 6 year-old children attending nursery classes of three public schools. Data were collected through clinical examinations and self-completed questionnaires. The main analyses were carried out on the imputed data set. The validity of content, face, construct, discriminant and convergent and as well as the reliability of internal and test-retest of the ECOHIS were evaluated. Sensitivity analysis was performed to examine the effect of the complete case analysis for managing "Don't know" responses on the validity and reliability of the ECOHIS.</p> <p>Results</p> <p>The analysis of the imputed data set showed that Cronbach's alphas for the child and family sections were 0.92 and 0.84 respectively, and for the whole scale was 0.93. The intraclass correlation coefficient for test-retest was 0.86. The scale scores on the child and parent sections indicating worse quality of life were significantly associated with poor parental ratings of their child's oral health, high caries experience, higher gingival index scores and problem-orientated dental attendance, supporting its construct, convergent and discriminant validity. Sensitivity analysis showed that the mean imputation method and the complete case analysis did not have differing effects on the validity and reliability of the ECOHIS.</p> <p>Conclusions</p> <p>This study provided preliminary evidence concerning validity and reliability of the Turkish version of the scale among 5-6-year-old children. Future studies should be conducted on the ECOHIS to evaluate fully its psychometric properties in both community- based and clinically-based studies among parents of children younger than five. This study provides initial evidence that the ECOHIS aimed at children aged 0-5 years may be a useful tool for assessing the oral health quality of life in 6 year - old preschool children.</p

A Pleiotrophin C-terminus peptide induces anti-cancer effects through RPTPβ/ζ

<p>Abstract</p> <p>Background</p> <p>Pleiotrophin, also known as HARP (Heparin Affin Regulatory Peptide) is a growth factor expressed in various tissues and cell lines. Pleiotrophin participates in multiple biological actions including the induction of cellular proliferation, migration and angiogenesis, and is involved in carcinogenesis. Recently, we identified and characterized several pleiotrophin proteolytic fragments with biological activities similar or opposite to that of pleiotrophin. Here, we investigated the biological actions of P(122-131), a synthetic peptide corresponding to the carboxy terminal region of this growth factor.</p> <p>Results</p> <p>Our results show that P(122-131) inhibits <it>in vitro </it>adhesion, anchorage-independent proliferation, and migration of DU145 and LNCaP cells, which express pleiotrophin and its receptor RPTPβ/ζ. In addition, P(122-131) inhibits angiogenesis <it>in vivo</it>, as determined by the chicken embryo CAM assay. Investigation of the transduction mechanisms revealed that P(122-131) reduces the phosphorylation levels of Src, Pten, Fak, and Erk¹/₂. Finally, P(122-131) not only interacts with RPTPβ/ζ, but also interferes with other pleiotrophin receptors, as demonstrated by selective knockdown of pleiotrophin or RPTPβ/ζ expression with the RNAi technology.</p> <p>Conclusions</p> <p>In conclusion, our results demonstrate that P(122-131) inhibits biological activities that are related to the induction of a transformed phenotype in PCa cells, by interacing with RPTPβ/ζ and interfering with other pleiotrophin receptors. Cumulatively, these results indicate that P(122-131) may be a potential anticancer agent, and they warrant further study of this peptide.</p

DNA Replication Catalyzed by Herpes Simplex Virus Type 1 Proteins Reveals Trombone Loops at the Fork

Using purified replication factors encoded by herpes simplex virus type 1 and a 70-base minicircle template, we obtained robust DNA synthesis with leading strand products of >20,000 nucleotides and lagging strand fragments from 600 to 9,000 nucleotides as seen by alkaline gel electrophoresis. ICP8 was crucial for the synthesis on both strands. Visualization of the deproteinized products using electron microscopy revealed long, linear dsDNAs, and in 87%, one end, presumably the end with the 70-base circle, was single-stranded. The remaining 13% had multiple single-stranded segments separated by dsDNA segments 500 to 1,000 nucleotides in length located at one end. These features are diagnostic of the trombone mechanism of replication. Indeed, when the products were examined with the replication proteins bound, a dsDNA loop was frequently associated with the replication complex located at one end of the replicated DNA. Furthermore, the frequency of loops correlated with the fraction of DNA undergoing Okazaki fragment synthesis

Electricity generation from disaccharides using microbial fuel cells

Bu &ccedil;alışmada, lignosel&uuml;lozik biyok&uuml;tlelerin asit hidrolizatlarında yaygın olarak bulunan disakkaritlerden elektrik &uuml;retimi, tek odalı, hava-katot mikrobiyal yakıt h&uuml;creleri kullanılarak araştırılmıştır. Başlıca iki disakkariti (D-sellobiyoz, D-maltoz) kapsayan karbon kaynakları ile elektrik &uuml;retimi g&ouml;zlenmiştir. Sodyum asetat ile zenginleştirilmiş karışık bakteri k&uuml;lt&uuml;r&uuml;, test edilen b&uuml;t&uuml;n disakkaritlere kolayca adapte olmuştur. Yeni karbon kaynağına adaptasyon i&ccedil;in gerekli s&uuml;re de benzerlik g&ouml;sterdi. Test edilen disakkaritler i&ccedil;in elde edilen en y&uuml;ksek g&uuml;&ccedil; yoğunluğu, 0.44-0.66 mA cm-2 diren&ccedil; yoğunluğunda, sellobiyoz i&ccedil;in 1262&plusmn;5 mW m-2, maltoz i&ccedil;inse 1893&plusmn;67 mW m-2 olarak bulunmuştur. Kolombik yeterlik sellobiyoz i&ccedil;in y&uuml;zde 18, maltoz i&ccedil;inse y&uuml;zde 30 olarak bulunmuştur. Test edilen disakkaritler i&ccedil;in, en y&uuml;ksek volt eldesi ve substrat konsantrasyonu arasındaki ilişki 120 ohm dış diren&ccedil;te doygunluk kinetiği sonu&ccedil;ları ile uyumluluk g&ouml;stermiştir. &Ouml;n g&ouml;r&uuml;len en y&uuml;ksek volt &uuml;retimi substratın &ccedil;eşidine bağlı olarak, sellobiyoz i&ccedil;in 0.34 V, yarı doygunluk kinetik sabiti, 626 mg L- (R2= 0.971), maltoz i&ccedil;in ise 0.40 V ve yarı doygunluk kinetik sabiti 733 mg L-1 (R2= 0.998) olarak bulunmuştur. Test edilen disakkaritler i&ccedil;in y&uuml;zde 81&rsquo;nin &uuml;zerinde kimyasal oksijen talebinde azalma sağlanmıştır. Test edilen disakkaritlerin elektrik &uuml;retiminde karbon kaynağı olarak kullanılabileceği keşfedilmiştir. &Ccedil;alışmamızın sonu&ccedil;ları, lignosel&uuml;lozik maddelerden t&uuml;revli disakkaritlerin ve lignosel&uuml;loz t&uuml;revli maddelerin &ouml;n muamele ile mikrobiyal yakıt h&uuml;creleri i&ccedil;in uygun birer karbon kaynağı olabileceklerini g&ouml;stermiştir.&nbsp;Anahtar Kelimeler: Elektrik, disakkarit, mikrobiyal yakıt h&uuml;cresi, performans.Researches on the finding renewable energy alternatives to fossil fuels have been great attention in recent years. The production of fuel and energy from lignocellulosic biomass such as agricultural residues and woody biomass has drawn significant attention because of the abundance, ready availability and renewable nature of these resources. The main components of lignocellulosic biomass are cellulose, hemicelluloses and lignin. Our previous study indeed demonstrated that all monosaccharides that can be directly generated from hydrolysis of lignocellulosic biomass were good sources for electricity generation in MFCs. However, lignocellulosic biomass cannot be directly utilized by microorganisms in MFCs for electricity generation.  In other words, lignocellulosic material has to be converted to sugars or other low-molecular-weight compounds.  The most commonly used method of converting lignocellulosic biomass to the sugars is through a dilute-acid pre-treatment and subsequent acid- or enzymatic hydrolysis processes. The dilute-acid pretreatment and the subsequent acid hydrolysis generate a number of byproducts, such as furan derivatives, phenolic compounds and carboxylic acids Our previous study shows that most of the phenolic compunds and furan derivatives do not have inhbitory effect on electricity generation. However, upto know, there is no information about the electricity generation in air-cathode single chamber mediator-less microbial fuel cells from tested disaccharides.  The acid hydrolysates from lignocellulosic materials such as pine wood or corn stover supposedly contain severall monosaccharides and disaccaharides previously described. Our preliminary results show that sulfuric acid hydrolysation (10%) of pine wood flour generate electricity in MFCs. However, it is poorly understood whether all the disaccharides can be utilized by bacteria in an MFC for electricity generation. Microbial fuel cell (MFC) technology uses microorganisms to catalyze the direct production of electricity from organic materials, and provides a new method for green energy generation from biomass. Various organic materials, such as glucose, xylose, acetate, butyrate, lactate, etc. as well as those from waste streams such as wastewaters can be used to generate direct electicity by MFCs. In this study, the direct production of electricity from disaccharides of lignocellulosic biomass was examined MFC performances by the disaccharides were evaluated as the following parameters: (1) Voltage generation, (2) power density generation, (3) Coulobic efficiency, (4) the removal of chemical oxygen demand and the effect of substrate concentration on electricity generation. Voltage was measured using a multimeter with a data acquisition system. Power density (mW m-2) was calculated according to P=IV/A, where I is the current, V voltage, and A the projected area of the anode. Electricity was produced from all disaccharides tested, including D-maltose and D-cellobiose. The mixed bacterial culture enriched using sodium acetate as a carbon source adapted well to all carbon sources tested. The adaptation time, which was defined as the time between adding a disaccharide solution to a MFC and reaching a maximum power output at 1000 W, was similar for each disaccharide. However, once the bacteria adapted to a new disaccharide, electricity was quickly recovered when the disaccharide solution was refilled. Maximum power density obtained from these disaccharides were 1262±5 mW m-2 for D-cellobiose, 1893±67 mW m-2 for D-maltose at current density of 0.44 and 0.66 mA cm-2, respectively. For two disaccharides tested, the maximum voltage output at 120  external resistance initially increased with the disaccharide concentration; however, further increases above a certain level did not improve the electricity generation Coulombic efficiency was 18% for D-cellobiose and 30% for D-maltose. For disaccharides tested, the relationship between the maximum voltage output and the substrate concentration appeared to follow saturation kinetics at 120  external resistance. The estimated maximum voltage output ranged between 0.34-0.40 V and half-saturation kinetic constants of 626 to 733 mg L-1for D-cellobiose and D-maltose, respectively. Chemical oxygen demand (COD) removal was over 81 % for disaccharides tested. Results from this study indicated that lignocellulosic biomass-derived disaccharides might be a suitable resource for electricity generation using MFC technology. Keywords: Electricity, microbial fuel cell, disaccharide, performance

Mitochondrial Single-stranded DNA-binding Proteins Stimulate the Activity of DNA Polymerase γ by Organization of the Template DNA

The activity of the mitochondrial replicase, DNA polymerase γ (Pol γ) is stimulated by another key component of the mitochondrial replisome, the mitochondrial single-stranded DNA-binding protein (mtSSB). We have performed a comparative analysis of the human and Drosophila Pols γ with their cognate mtSSBs, evaluating their functional relationships using a combined approach of biochemical assays and electron microscopy. We found that increasing concentrations of both mtSSBs led to the elimination of template secondary structure and gradual opening of the template DNA, through a series of visually similar template species. The stimulatory effect of mtSSB on Pol γ on these ssDNA templates is not species-specific. We observed that human mtSSB can be substituted by its Drosophila homologue, and vice versa, finding that a lower concentration of insect mtSSB promotes efficient stimulation of either Pol. Notably, distinct phases of the stimulation by both mtSSBs are distinguishable, and they are characterized by a similar organization of the template DNA for both Pols γ. We conclude that organization of the template DNA is the major factor contributing to the stimulation of Pol γ activity. Additionally, we observed that human Pol γ preferentially utilizes compacted templates, whereas the insect enzyme achieves its maximal activity on open templates, emphasizing the relative importance of template DNA organization in modulating Pol γ activity and the variation among systems

Conformational landscapes of DNA polymerase I and mutator derivatives establish fidelity checkpoints for nucleotide insertion

The fidelity of DNA polymerases depends on conformational changes that promote the rejection of incorrect nucleotides before phosphoryl transfer. Here, we combine single-molecule FRET with the use of DNA polymerase I and various fidelity mutants to highlight mechanisms by which active-site side chains influence the conformational transitions and free-energy landscape that underlie fidelity decisions in DNA synthesis. Ternary complexes of high fidelity derivatives with complementary dNTPs adopt mainly a fully closed conformation, whereas a conformation with a FRET value between those of open and closed is sparsely populated. This intermediate-FRET state, which we attribute to a partially closed conformation, is also predominant in ternary complexes with incorrect nucleotides and, strikingly, in most ternary complexes of low-fidelity derivatives for both correct and incorrect nucleotides. The mutator phenotype of the low-fidelity derivatives correlates well with reduced affinity for complementary dNTPs and highlights the partially closed conformation as a primary checkpoint for nucleotide selection

Harnessing the potential of ligninolytic enzymes for lignocellulosic biomass pretreatment

Abundant lignocellulosic biomass from various industries provides a great potential feedstock for the production of value-added products such as biofuel, animal feed, and paper pulping. However, low yield of sugar obtained from lignocellulosic hydrolysate is usually due to the presence of lignin that acts as a protective barrier for cellulose and thus restricts the accessibility of the enzyme to work on the cellulosic component. This review focuses on the significance of biological pretreatment specifically using ligninolytic enzymes as an alternative method apart from the conventional physical and chemical pretreatment. Different modes of biological pretreatment are discussed in this paper which is based on (i) fungal pretreatment where fungi mycelia colonise and directly attack the substrate by releasing ligninolytic enzymes and (ii) enzymatic pretreatment using ligninolytic enzymes to counter the drawbacks of fungal pretreatment. This review also discusses the important factors of biological pretreatment using ligninolytic enzymes such as nature of the lignocellulosic biomass, pH, temperature, presence of mediator, oxygen, and surfactant during the biodelignification process