The effects and interactions of three invasive fish species introduced to the aquatic ecosystem of a Turkish Lake (Eğirdir Lake)

We studied feeding behavior and prey selection of topmouth gudgeon (Pseudorasbora parva), big-scale sand smelt (Atherina boyeri) and pike-perch (Sander lucioperca) in Lake E?irdir, the second largest freshwater lake in Turkey. Fish specimens were collected between January and August in 2010 and 2011 using gill-nets and purse seines. A total of 941 specimens were analyzed for stomach contents analysis. We expressed the importance of the food items present in their guts with the relative importance index (IRI) and estimated their diet selectivity indices with Pearre’s index. Pseudorasbora parva had a diverse diet comprising mainly Nitokra hibernica (copepod), Chydorus sphaericus, and Bosmina longirostris (cladoceran) (each, at p?<?0.01), but Chironomus sp. (insect) was not a significant component of its diet (p?>?0.05). Big-scale sand smelt often preferred B. longirostris, N. hibernica, and Alona quadrangularis (each at p?<?0.01). Pike-perch positively, but not statistically significant, selected Atherina boyeri (p?>?0.05), Carassius gibelio was not preferred by pike-perch as food item (p?>?0.05). Our results indicate that invasive species altered the food chain in Lake E?irdir. Thus, because these fish species constitute a major threat for native fish species for food and breeding grounds, extensive care should be taken to prevent invasive fish species entering lakes in Turkey.

     

Human Schlafen 5 (SLFN5) Is a Regulator of Motility and Invasiveness of Renal Cell Carcinoma Cells

We provide evidence that human SLFN5, an interferon (IFN)-inducible member of the Schlafen (SLFN) family of proteins, exhibits key roles in controlling motility and invasiveness of renal cell carcinoma (RCC) cells. Our studies define the mechanism by which this occurs, demonstrating that SLFN5 negatively controls expression of the matrix metalloproteinase 1 gene (MMP-1), MMP-13, and several other genes involved in the control of malignant cell motility. Importantly, our data establish that SLFN5 expression correlates with a better overall survival in a large cohort of patients with RCC. The inverse relationship between SLFN5 expression and RCC aggressiveness raises the possibility of developing unique therapeutic approaches in the treatment of RCC, by modulating SLFN5 expression.     

Free-Energy Landscape and Characteristic Forces for the Initiation of DNA Unzipping

DNA unzipping, the separation of its double helix into single strands, is crucial in modulating a host of genetic processes. Although the large-scale separation of double-stranded DNA has been studied with a variety of theoretical and experimental techniques, the minute details of the very first steps of unzipping are still unclear. Here, we use atomistic molecular-dynamics simulations, coarse-grained simulations, and a statistical-mechanical model to study the initiation of DNA unzipping by an external force. Calculation of the potential of mean force profiles for the initial separation of the first few terminal basepairs in a DNA oligomer revealed that forces ranging between 130 and 230 pN are needed to disrupt the first basepair, and these values are an order of magnitude larger than those needed to disrupt basepairs in partially unzipped DNA. The force peak has an echo of ∼50 pN at the distance that unzips the second basepair. We show that the high peak needed to initiate unzipping derives from a free-energy basin that is distinct from the basins of subsequent basepairs because of entropic contributions, and we highlight the microscopic origin of the peak. To our knowledge, our results suggest a new window of exploration for single-molecule experiments.     

The effect of Helicobacter pylori and economic status on growth parameters and leptin, ghrelin, and insulin-like growth factor (IGF)-I concentrations in children

Background: It was suggested that gastric colonization with Helicobacter pylori (H. pylori) was associated with suboptimal nutrition and growth in childhood. Furthermore, several studies indicated a relationship between H. pylori colonization and alterations in the circulating levels of growth‐related molecules (GRM). Accordingly, in this study, we investigate the effect of H. pylori infection on GRMs and on the growth of healthy school children, taking into consideration the effect of their economic status (ES) and anthropometric indices of their parents. Methods: To acquire sociodemographic and anthropometric nutritional parameters and to detect H. pylori‐specific serum IgG antibodies and growth‐related molecules, we evaluated a total of 473 children attending four different primary and secondary schools in Istanbul. Subsequently, we assessed the effect of H. pylori on growth‐related parameters (weight for age SDS, height for age SDS, BMI SDS, TSF, and waist‐to‐hip ratio) and on GRMs (leptin, ghrelin, and insulin‐like growth factor‐1 (IGF‐1)), controlling for age, gender, family income, household crowding (HC), breastfeeding, maternal and paternal BMI SDS, and midparental height SDS with complex statistical models. Results: Of the 473 children (275 F/198 M, age 6–15 years; mean: 10.3 ± 0.1 years), 161 (34%) were H. pylori‐positive. The prevalence of H. pylori was significantly higher in lower economic status (ES) groups, in children living in crowded houses, and in older age groups. Using simple statistical models, we did not find any significant associations between H. pylori infection and the growth parameters. However, in complex models for height for age SDS and for weight for age SDS, there was a significant interaction between H. pylori infection status and ES. Whereas in H. pylori‐positive subjects, mid‐income family children were both taller and heavier than the low‐income group, there was no such an association in H. pylori‐negative subjects. Among biochemical parameters, only ghrelin levels were associated with H. pylori infection in all models. Leptin levels were associated with HC in girls, whereas none of the parameters was significantly associated with leptin levels in boys. For IGF‐1 levels, for boys, age and maternal BMI, and for girls, age and HC were significantly associated with IGF‐1 levels. Conclusion: We suggest that H. pylori may impair growth significantly only in susceptible children where unfavorable socioeconomic conditions facilitate its action, probably through mechanisms, at least in part, involving growth‐related molecules.     

An Evaluation of Risk Factors in Pregnant Women with <Emphasis Type="Italic">Candida</Emphasis> Vaginitis and the Diagnostic Value of Simultaneous Vaginal and Rectal Sampling

In this study, we investigated the epidemiological characteristics of VVC among pregnant women. We conducted a prospective survey among 372 pregnant women to investigate the prevalence, clinical forms, etiological agents, and predisposing factors of VVC. In addition, we determined the relationship between vaginal and rectal flora by simultaneously obtaining one high vaginal swab and one rectal swab from each patient using sterile cotton-tipped swabs. Furthermore, we compared the recovery and identification performances of chromID Candida agar to Sabouraud dextrose agar with gentamicin and chloramphenicol. Clinically and mycologically confirmed cases of VVC were detected in 139 (37.4%) and vaginal colonization described in 42 (11.3%) of 372 pregnant women. Rectal cultures were also positive in 98 of the 139 (70.5%) VVC cases. Candida albicans and C. glabrata were identified in vaginal samples in 58.0 versus 19.0% and from rectal samples in 49.0 versus 13.5%, respectively. Increases in gestational week and gravidae were identified to be statistically significant in patients with acute VVC (AVVC) and symptomatic recurrent VVC (RVVC), and asymptomatic RVVC (P = 0.04 and P = 0.03, respectively). In the laboratory diagnosis of VVC, specifically tailored chromogenic media are reliable tools for both the recovery and rapid identification of common Candida spp., particularly C. albicans, as well as for the detection of polyfungal populations in vaginal samples (P > 0.05). In addition, rectal colonization is a common finding in cases of AVVC and symptomatic-RVVC cases and corresponds well with the presence of the same yeast species in the vagina.     

Serum salusin-alpha level in rheumatoid arthritis

Rheumatoid arthritis (RA), a chronic inflammatory disease, leads to early and accelerated atherosclerosis; however, its pathogenesis is not yet fully documented. Salusin-α and β are novel bioactive peptides. Salusin-α suppresses macrophage foam cell formation, while salusin-β stimulates. Moreover, decreased serum salusin-α level has been reported previously in patients with coronary artery disease. The aims of the study were to assess serum salusin-α level and its association with predictors of atherosclerosis in a cohort of patients with RA. The study included 56 RA patients, 37 Behcet's disease (BD) patients, and 29 healthy controls (HC). TNF-α, IL-6 and salusin-α levels, homeostasis model assessment (HOMA-IR) index and common carotid intima-media thickness (IMT) were determined. In the RA and BD groups, salusin-α levels (p<0.001 and p<0.01, respectively) and IMTs (p<0.001 for both) were higher compared to the HC group. However, the level of salusin-α was not directly associated with the IMT in all the groups. Serum salusin-α levels are increased in RA and BD, although they have increased IMT. Salusin-α has been reported to have anti-atherogenic effects in previous studies. However, it seems that salusin-α does not directly affect the atherogenesis in RA and BD. Further studies are needed to understand the regulation of salusin-α and determination of its relations with the predictors of atherosclerosis in RA and BD.     

Genome-wide identification of genes that play a role in boron stress response in yeast

Boron is an essential micronutrient for plants and it is either necessary or beneficial for animals. Studies identified only few genes related to boron metabolism thus far and details of how boron is imported into cells and used in cell metabolism are largely unknown. In order to identify genes that play roles in boron metabolism, we screened the entire set of yeast haploid deletion mutants and identified 6 mutants that were resistant to toxic levels of boron, and 21 mutants that were highly sensitive to boron treatment. Furthermore, we performed a proteomic approach to identify additional proteins that are significantly up-regulated by boron treatment. Our results revealed many genes and pathways related to boron stress response and suggest a possible link between boron toxicity and translational control.